makeObservable/makeAutoObservable AdditionalKeys provides only the illusion of type safety

[devuxer]

Limitation 8 says:

By default TypeScript will not allow you to annotate private fields. This can be overcome by explicitly passing the relevant private fields as generic argument, like this: makeObservable<MyStore, "privateField" | "privateField2">(this, { privateField: observable, privateField2: observable })

I'm struggling to see how you gain any type safety by specifying the AdditionalKeys ( "privateField" | "privateField2" in this case). You could actually make up anything you want for those keys, and TypeScript would be none the wiser. While I normally avoid using any like the plague, I'd argue you that in this case, it's actually the correct thing to do. It's a signal to anyone reading the code
that the overrides that aren't part of the public API not able to be type safe.

I think the documentation should make this more clear.