VS Code variable inspection / watch does not work for default imports in NodeJS environment

TypeScript Version: 3.7.5
VSCode Version: 1.41.1 2019-12-18

Search Terms:
VSCode TypeScript Default Import Renamed Can't Debug Watch Inspect

Code

filea.ts

const a: string = "hello";
export default a;

fileb.ts

import a from "./filea"
console.log(a);

tsconfig.json

{
   "compilerOptions": {
      "lib": [ "es6" ],
      "moduleResolution": "node",
      "module": "commonjs",
      "target": "es6",
      "sourceMap": true
   }
}

Expected behavior:

Works correctly in runtime
Variable a (imported one) can be inspected

Actual behavior:

Works correctly in runtime
Variable a (imported one) can't be inspected neither watched as VS Code says: not available

The problem is the variable a does not exist at runtime as the import is transpiled as:

const filea_1 = require("./filea");
console.log(filea_1.default);

Watching of filea_1.default works correctly, of course.

I am not sure if there is additional mapping somewhere, but everything else works well (breakpoints, other variable inspections...)

maybe the default imports can be transpiled as

const a = require("./filea").default;
console.log(a);

Start with filea.ts, fileb.ts, and tsconfig.json, then inspect the emitted CommonJS JavaScript and its source map while reproducing the watch behavior in VS Code. Determine whether default-import names can be mapped to the generated filea_1.default access without breaking existing runtime output. Done means the imported variable a can be inspected and watched in the NodeJS environment.