Typescript module augmentation with ambient declaration - typescript-typings

Question

Just a question on whether this problem with typings is possible to fix with an ambient type/module declaration and how. In actuality I'll see about getting the typings fixed in the library in question, but sometimes that's not possible.
I'm trying #finos/perspective. There is a worker object that has a factory method for creating a table: worker.table.
#finos/perspective/index.d.ts
export type PerspectiveWorker = {
table(data: TableData, options?: TableOptions): Table;
};
The data parameter is of type TableData.
#finos/perspective/index.d.ts
export type TableData = string | Array<object> | {[key: string]: Array<object>} | {[key: string]: string};
The problem is that worker.table() also actually takes an ArrayBuffer to allow creation of a table from an Apache Arrow binary buffer. So, TableData should have | ArrayBuffer added to it's type signature, but since it does not have this typescript is complaining:
Argument of type 'ArrayBuffer' is not assignable to parameter of type 'string | object[] | { [key: string]: object[]; } | { [key: string]: string; } | Schema'.
Type 'ArrayBuffer' is not assignable to type 'Schema'.
Index signature is missing in type 'ArrayBuffer'.ts(2345)
If I manually edit #finos/perspective/index.d.ts and add | ArrayBuffer as in:
export type TableData = string | Array<object> | {[key: string]: Array<object>} | {[key: string]: string} | ArrayBuffer;
Then typescript stops complaining (and the code actually works regardless of whether typescript complains or not).
Is there a way to fix this with an ambient declaration?
tsconfig.json
{
"compilerOptions": {
"target": "ESNext",
"module": "commonjs",
"skipLibCheck": true,
"lib": ["dom", "esnext", "ESNext.AsyncIterable"],
"declaration": true,
"outDir": "lib",
"rootDir": "src",
"strict": true,
"types": ["node"],
"esModuleInterop": true,
"resolveJsonModule": true,
"downlevelIteration": true,
"sourceMap": true,
"allowSyntheticDefaultImports": true,
"moduleResolution": "node",
"typeRoots": ["./node_modules/#types", "./src/_declarations"]
},
"exclude": ["node_modules"]
}
src/_declarations/perspective.d.ts
import type { TableData } from "#finos/perspective";
declare module "#finos/perspective" {
export type TableData =
| string
| Array<Record<string, unknown>>
| { [key: string]: Array<Record<string, unknown>> }
| { [key: string]: string }
| ArrayBuffer;
}
I also tried:
export type TableData = TableData | ArrayBuffer;
All of this is failing to stop typescript from complaining. I sometimes struggle with things like this, trying to augment a third-party module via ambient type declarations and wonder if anyone could shed some light on how this might be solvable without changing the third-party library.