diff --git a/packages/api-contract/src/base/Contract.ts b/packages/api-contract/src/base/Contract.ts
index 5e07693dd3..4bf2e2f2cd 100644
--- a/packages/api-contract/src/base/Contract.ts
+++ b/packages/api-contract/src/base/Contract.ts
@@ -11,7 +11,7 @@ import { ContractRead, MapMessageExec, MapMessageRead } from './types';
 import BN from 'bn.js';
 import { map } from 'rxjs/operators';
 import ApiBase from '@polkadot/api/base';
-import { assert, bnToBn, isFunction, isObject, isUndefined, stringCamelCase } from '@polkadot/util';
+import { assert, bnToBn, isFunction, isUndefined, stringCamelCase } from '@polkadot/util';
 
 import Abi from '../Abi';
 import { formatData } from '../util';
@@ -20,9 +20,7 @@ import Base from './Base';
 const ERROR_NO_CALL = 'Your node does not expose the contracts.call RPC. This is most probably due to a runtime configuration.';
 
 // map from a JSON result to current-style ContractExecResult
-function mapExecResult (registry: Registry, json: AnyJson): ContractExecResult {
-  assert(isObject(json) && !Array.isArray(json), 'Invalid JSON result retrieved');
-
+function mapExecResult (registry: Registry, json: Record<string, AnyJson>): ContractExecResult {
   if (!Object.keys(json).some((key) => ['error', 'success'].includes(key))) {
     return registry.createType('ContractExecResult', json);
   }
diff --git a/packages/api-derive/src/treasury/proposals.ts b/packages/api-derive/src/treasury/proposals.ts
index 40d60df758..0df38133fd 100644
--- a/packages/api-derive/src/treasury/proposals.ts
+++ b/packages/api-derive/src/treasury/proposals.ts
@@ -51,9 +51,7 @@ function retrieveProposals (api: ApiInterfaceRx, proposalCount: ProposalIndex, a
   const count = proposalCount.toNumber();
 
   for (let index = 0; index < count; index++) {
-    const isApproval = approvalIds.some((id): boolean => id.eqn(index));
-
-    if (!isApproval) {
+    if (!approvalIds.some((id) => id.eqn(index))) {
       proposalIds.push(api.registry.createType('ProposalIndex', index));
     }
   }
diff --git a/packages/api-derive/src/type/HeaderExtended.ts b/packages/api-derive/src/type/HeaderExtended.ts
index f645501687..5e6f712ed2 100644
--- a/packages/api-derive/src/type/HeaderExtended.ts
+++ b/packages/api-derive/src/type/HeaderExtended.ts
@@ -36,9 +36,9 @@ export default class HeaderExtended extends _Header {
   /**
    * @description Creates a human-friendly JSON representation
    */
-  public toHuman (isExtended?: boolean): AnyJson {
+  public toHuman (isExtended?: boolean): Record<string, AnyJson> {
     return {
-      ...super.toHuman(isExtended) as { [index: string]: AnyJson },
+      ...super.toHuman(isExtended),
       author: this.author
         ? this.author.toHuman()
         : undefined
@@ -48,9 +48,9 @@ export default class HeaderExtended extends _Header {
   /**
    * @description Creates the JSON representation
    */
-  public toJSON (): AnyJson {
+  public toJSON (): Record<string, AnyJson> {
     return {
-      ...super.toJSON() as { [index: string]: AnyJson },
+      ...super.toJSON(),
       author: this.author
         ? this.author.toJSON()
         : undefined
diff --git a/packages/api-derive/src/type/SignedBlockExtended.ts b/packages/api-derive/src/type/SignedBlockExtended.ts
index 4389c42428..da98e5de43 100644
--- a/packages/api-derive/src/type/SignedBlockExtended.ts
+++ b/packages/api-derive/src/type/SignedBlockExtended.ts
@@ -36,9 +36,9 @@ export default class BlockExtended extends _SignedBlock {
   /**
    * @description Creates a human-friendly JSON representation
    */
-  public toHuman (isExtended?: boolean): AnyJson {
+  public toHuman (isExtended?: boolean): Record<string, AnyJson> {
     return {
-      ...super.toHuman(isExtended) as { [index: string]: AnyJson },
+      ...super.toHuman(isExtended),
       author: this.author
         ? this.author.toHuman()
         : undefined
@@ -48,9 +48,9 @@ export default class BlockExtended extends _SignedBlock {
   /**
    * @description Creates the JSON representation
    */
-  public toJSON (): AnyJson {
+  public toJSON (): Record<string, AnyJson> {
     return {
-      ...super.toJSON() as { [index: string]: AnyJson },
+      ...super.toJSON(),
       author: this.author
         ? this.author.toJSON()
         : undefined
diff --git a/packages/api/src/base/Decorate.ts b/packages/api/src/base/Decorate.ts
index f2ebca90e6..d52a11018d 100644
--- a/packages/api/src/base/Decorate.ts
+++ b/packages/api/src/base/Decorate.ts
@@ -290,12 +290,10 @@ export default abstract class Decorate<ApiType extends ApiTypes> extends Events
     // eslint-disable-next-line @typescript-eslint/no-unsafe-return
     return decorateMethod((calls: QueryableStorageMultiArg<ApiType>[]): Observable<Codec[]> =>
       this._rpcCore.state.subscribeStorage(
-        calls.map((arg: QueryableStorageMultiArg<ApiType>): [QueryableStorageEntry<ApiType>, ...Arg[]] =>
-          // the input is a QueryableStorageEntry, convert to StorageEntry
-          // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+        calls.map((arg: QueryableStorageMultiArg<ApiType>) =>
           Array.isArray(arg)
             ? [arg[0].creator, ...arg.slice(1)]
-            : [arg.creator] as any)));
+            : [arg.creator])));
   }
 
   protected _decorateExtrinsics<ApiType extends ApiTypes> ({ tx }: DecoratedMeta, decorateMethod: DecorateMethod<ApiType>): SubmittableExtrinsics<ApiType> {
diff --git a/packages/api/src/promise/Combinator.ts b/packages/api/src/promise/Combinator.ts
index 1a3cbdb2a5..8410cd33bd 100644
--- a/packages/api/src/promise/Combinator.ts
+++ b/packages/api/src/promise/Combinator.ts
@@ -46,9 +46,7 @@ export default class Combinator<T extends any[] = any[]> {
   }
 
   protected _allHasFired (): boolean {
-    if (!this.#allHasFired) {
-      this.#allHasFired = this.#fired.filter((hasFired): boolean => !hasFired).length === 0;
-    }
+    this.#allHasFired ||= this.#fired.filter((hasFired): boolean => !hasFired).length === 0;
 
     return this.#allHasFired;
   }
diff --git a/packages/rpc-core/src/index.ts b/packages/rpc-core/src/index.ts
index 3524f5e484..ff7655b92c 100644
--- a/packages/rpc-core/src/index.ts
+++ b/packages/rpc-core/src/index.ts
@@ -167,11 +167,9 @@ export default class Rpc implements RpcInterface {
 
     // decorate the sections with base and user methods
     this.sections.forEach((sectionName): void => {
-      if (!(this as Record<string, unknown>)[sectionName as Section]) {
-        (this as Record<string, unknown>)[sectionName as Section] = {};
-      }
+      (this as Record<string, unknown>)[sectionName as Section] ||= {};
 
-      const section = (this as Record<string, unknown>)[sectionName as Section] as Record<string, any>;
+      const section = this[sectionName as Section] as Record<string, unknown>;
 
       Object
         .entries({
@@ -179,11 +177,7 @@ export default class Rpc implements RpcInterface {
           ...this._createInterface(sectionName, userRpc[sectionName] || {})
         })
         .forEach(([key, value]): void => {
-          // we don't want to clobber existing, i.e. when this is called again after chain is determined
-          if (!section[key]) {
-            // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-            section[key] = value;
-          }
+          section[key] ||= value;
         });
     });
   }
diff --git a/packages/types/src/codec/Enum.ts b/packages/types/src/codec/Enum.ts
index eb3ed370c0..808db2331b 100644
--- a/packages/types/src/codec/Enum.ts
+++ b/packages/types/src/codec/Enum.ts
@@ -152,27 +152,21 @@ export default class Enum implements Codec {
           const askey = `as${name}`;
           const iskey = `is${name}`;
 
-          // do not clobber existing properties on the object
-          // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-          if (isUndefined((this as any)[iskey])) {
+          isUndefined(this[iskey as keyof this]) &&
             Object.defineProperty(this, iskey, {
               enumerable: true,
-              get: (): boolean => this.type === _key
+              get: () => this.type === _key
             });
-          }
 
-          // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-          if (isUndefined((this as any)[askey])) {
+          isUndefined(this[askey as keyof this]) &&
             Object.defineProperty(this, askey, {
               enumerable: true,
               get: (): Codec => {
-                // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-                assert((this as any)[iskey], `Cannot convert '${this.type}' via ${askey}`);
+                assert(this[iskey as keyof this], `Cannot convert '${this.type}' via ${askey}`);
 
                 return this.value;
               }
             });
-          }
         });
       }
     };
diff --git a/packages/types/src/codec/Json.ts b/packages/types/src/codec/Json.ts
index 4d532041f9..12efa24f3a 100644
--- a/packages/types/src/codec/Json.ts
+++ b/packages/types/src/codec/Json.ts
@@ -31,18 +31,12 @@ export default class StructAny extends Map<string, any> implements Codec {
 
     this.registry = registry;
 
-    // like we are doing with structs, add the keys as getters
     decoded.forEach(([key]): void => {
-      // do not clobber existing properties on the object
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-      if (!isUndefined((this as any)[key])) {
-        return;
-      }
-
-      Object.defineProperty(this, key, {
-        enumerable: true,
-        get: (): Codec | undefined => this.get(key) as Codec
-      });
+      isUndefined(this[key as keyof this]) &&
+        Object.defineProperty(this, key, {
+          enumerable: true,
+          get: (): Codec | undefined => this.get(key) as Codec
+        });
     });
   }
 
@@ -84,14 +78,14 @@ export default class StructAny extends Map<string, any> implements Codec {
   /**
    * @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
    */
-  public toHuman (): AnyJson {
+  public toHuman (): Record<string, AnyJson> {
     return this.toJSON();
   }
 
   /**
    * @description Converts the Object to JSON, typically used for RPC transfers
    */
-  public toJSON (): AnyJson {
+  public toJSON (): Record<string, AnyJson> {
     return [...this.entries()].reduce((json: Record<string, AnyJson>, [key, value]): Record<string, AnyJson> => {
       json[key] = value as AnyJson;
 
diff --git a/packages/types/src/codec/Map.ts b/packages/types/src/codec/Map.ts
index 8460d9baf7..c5b94c5662 100644
--- a/packages/types/src/codec/Map.ts
+++ b/packages/types/src/codec/Map.ts
@@ -152,8 +152,8 @@ export default class CodecMap<K extends Codec = Codec, V extends Codec = Codec>
   /**
    * @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
    */
-  public toHuman (isExtended?: boolean): AnyJson {
-    const json: AnyJson = {};
+  public toHuman (isExtended?: boolean): Record<string, AnyJson> {
+    const json: Record<string, AnyJson> = {};
 
     this.forEach((v: V, k: K) => {
       json[k.toString()] = v.toHuman(isExtended);
@@ -165,8 +165,8 @@ export default class CodecMap<K extends Codec = Codec, V extends Codec = Codec>
   /**
    * @description Converts the Object to JSON, typically used for RPC transfers
    */
-  public toJSON (): AnyJson {
-    const json: AnyJson = {};
+  public toJSON (): Record<string, AnyJson> {
+    const json: Record<string, AnyJson> = {};
 
     this.forEach((v: V, k: K) => {
       json[k.toString()] = v.toJSON();
diff --git a/packages/types/src/codec/Set.ts b/packages/types/src/codec/Set.ts
index 5f52395ffc..ec8dcd5f8f 100644
--- a/packages/types/src/codec/Set.ts
+++ b/packages/types/src/codec/Set.ts
@@ -100,14 +100,11 @@ export default class CodecSet extends Set<string> implements Codec {
           const name = stringUpperFirst(stringCamelCase(_key));
           const iskey = `is${name}`;
 
-          // do not clobber existing properties on the object
-          // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-          if (isUndefined((this as any)[iskey])) {
+          isUndefined(this[iskey as keyof this]) &&
             Object.defineProperty(this, iskey, {
               enumerable: true,
               get: (): boolean => this.strings.includes(_key)
             });
-          }
         });
       }
     };
diff --git a/packages/types/src/codec/Struct.ts b/packages/types/src/codec/Struct.ts
index e43d126a2f..1ebb1e9a82 100644
--- a/packages/types/src/codec/Struct.ts
+++ b/packages/types/src/codec/Struct.ts
@@ -155,22 +155,25 @@ export default class Struct<
       constructor (registry: Registry, value?: unknown) {
         super(registry, Types, value as string, jsonMap);
 
-        (Object.keys(Types) as (keyof S)[]).forEach((key): void => {
-          // do not clobber existing properties on the object
-          // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-          if (!isUndefined((this as any)[key])) {
-            return;
-          }
-
-          Object.defineProperty(this, key, {
-            enumerable: true,
-            get: (): Codec | undefined => this.get(key)
-          });
+        Object.keys(Types).forEach((key): void => {
+          isUndefined(this[key as keyof this]) &&
+            Object.defineProperty(this, key, {
+              enumerable: true,
+              get: (): Codec | undefined => this.get(key as keyof S)
+            });
         });
       }
     };
   }
 
+  public static typesToMap (registry: Registry, Types: Record<string, Constructor>): Record<string, string> {
+    return Object.entries(Types).reduce((result: Record<string, string>, [key, Type]): Record<string, string> => {
+      result[key] = registry.getClassName(Type) || new Type(registry).toRawType();
+
+      return result;
+    }, {});
+  }
+
   /**
    * @description The available keys for this enum
    */
@@ -264,37 +267,27 @@ export default class Struct<
   /**
    * @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
    */
-  public toHuman (isExtended?: boolean): AnyJson {
-    return [...this.keys()].reduce((json, key): Record<keyof S, AnyJson> => {
+  public toHuman (isExtended?: boolean): Record<string, AnyJson> {
+    return [...this.keys()].reduce((json: Record<string, AnyJson>, key): Record<string, AnyJson> => {
       const value = this.get(key);
 
-      json[key] = value && value.toHuman(isExtended);
+      json[key as string] = value && value.toHuman(isExtended);
 
       return json;
-    }, {} as Record<keyof S, AnyJson>);
+    }, {});
   }
 
   /**
    * @description Converts the Object to JSON, typically used for RPC transfers
    */
-  public toJSON (): AnyJson {
-    // FIXME the return type string is only used by Extrinsic (extends Struct),
-    // but its toJSON is the hex value
-    return [...this.keys()].reduce((json, key): Record<keyof S, AnyJson> => {
+  public toJSON (): Record<string, AnyJson> {
+    return [...this.keys()].reduce((json: Record<string, AnyJson>, key): Record<string, AnyJson> => {
       const jsonKey = this.#jsonMap.get(key) || key;
       const value = this.get(key);
 
-      json[jsonKey] = value && value.toJSON();
+      json[jsonKey as string] = value && value.toJSON();
 
       return json;
-    }, {} as Record<keyof S, AnyJson>);
-  }
-
-  public static typesToMap (registry: Registry, Types: Record<string, Constructor>): Record<string, string> {
-    return Object.entries(Types).reduce((result: Record<string, string>, [key, Type]): Record<string, string> => {
-      result[key] = registry.getClassName(Type) || new Type(registry).toRawType();
-
-      return result;
     }, {});
   }
 
diff --git a/packages/types/src/extrinsic/ExtrinsicEra.ts b/packages/types/src/extrinsic/ExtrinsicEra.ts
index afd948387f..199bb44ca1 100644
--- a/packages/types/src/extrinsic/ExtrinsicEra.ts
+++ b/packages/types/src/extrinsic/ExtrinsicEra.ts
@@ -67,12 +67,12 @@ export class MortalEra extends Tuple {
 
   /** @internal */
   private static _decodeMortalEra (registry: Registry, value?: MortalMethod | Uint8Array | number[] | string): MortalEraValue {
-    if (isU8a(value) || isHex(value) || Array.isArray(value)) {
+    if (!value) {
+      return [new U64(registry), new U64(registry)];
+    } else if (isU8a(value) || isHex(value) || Array.isArray(value)) {
       return MortalEra._decodeMortalU8a(registry, u8aToU8a(value));
     } else if (isObject(value)) {
       return MortalEra._decodeMortalObject(registry, value);
-    } else if (!value) {
-      return [new U64(registry), new U64(registry)];
     }
 
     throw new Error('Invalid data passed to Mortal era');
diff --git a/packages/types/src/generic/Call.ts b/packages/types/src/generic/Call.ts
index 8275b5e81e..bf9c0cd22c 100644
--- a/packages/types/src/generic/Call.ts
+++ b/packages/types/src/generic/Call.ts
@@ -231,7 +231,7 @@ export default class Call extends Struct implements IMethod {
   /**
    * @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
    */
-  public toHuman (isExpanded?: boolean): AnyJson {
+  public toHuman (isExpanded?: boolean): Record<string, AnyJson> {
     let call: CallFunction | undefined;
 
     try {
diff --git a/packages/types/src/generic/Event.ts b/packages/types/src/generic/Event.ts
index efe6fa44f7..a3ddf5c8a6 100644
--- a/packages/types/src/generic/Event.ts
+++ b/packages/types/src/generic/Event.ts
@@ -84,9 +84,7 @@ export default class Event extends Struct {
   /** @internal */
   public static decodeEvent (registry: Registry, value: Uint8Array = new Uint8Array()): { DataType: Constructor<Null> | Constructor<EventData>; value?: { index: Uint8Array; data: Uint8Array } } {
     if (!value.length) {
-      return {
-        DataType: Null
-      };
+      return { DataType: Null };
     }
 
     const index = value.subarray(0, 2);
@@ -145,9 +143,15 @@ export default class Event extends Struct {
   /**
    * @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
    */
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  public toHuman (isExpanded?: boolean): AnyJson {
-    // FIXME May this human-friendly
-    return this.toJSON();
+  public toHuman (isExpanded?: boolean): Record<string, AnyJson> {
+    return {
+      method: this.method,
+      section: this.section,
+      ...(isExpanded
+        ? { documentation: this.meta.documentation.map((d) => d.toString()) }
+        : {}
+      ),
+      ...super.toHuman(isExpanded)
+    };
   }
 }
diff --git a/packages/types/src/types/helpers.ts b/packages/types/src/types/helpers.ts
index 3ffc0142aa..c774dad60e 100644
--- a/packages/types/src/types/helpers.ts
+++ b/packages/types/src/types/helpers.ts
@@ -5,15 +5,9 @@ import { Codec } from './codec';
 
 import BN from 'bn.js';
 
-// We cannot inline this into CodecArg, TS thrws up when building docs
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
 export type AnyFunction = (...args: any[]) => any;
 
-// eslint-disable-next-line no-use-before-define
-export type AnyJson = string | number | boolean | null | undefined | AnyJsonArray | { [index: string]: AnyJson };
-
-// eslint-disable-next-line @typescript-eslint/no-empty-interface
-interface AnyJsonArray extends Array<AnyJson> {}
+export type AnyJson = string | number | boolean | null | undefined | AnyJson[] | { [index: string]: AnyJson };
 
 export type AnyNumber = BN | BigInt | Uint8Array | number | string;