You can, and the rejection email even provides instructions for how to do so.

And where will you get the current list of all forbidden functions/APIs, not just those for this specific case with Electron?

Whatever symbols are found in the public header files in the /System/Library/Frameworks. Iirc, there are tools which look at a binary's used symbols and compare them to those headers.

Of course you can! How do you think Apple's checking your binaries?

Using some internal tool.

The internal tool is very likely using/parsing otool / ldd output and similar. eg cli tooling that comes with macOS itself

No, it’s almost certainly just a search for strings and looking through the symbol table.

That would be very easy to work around with dlopen and some string obfuscation. It's probably a bit more involved.

In practice it is pretty easy to slip things past the automated checks if you try to, which is one of the reasons they threaten you with a permaban for doing so.

exactly. Apparently Apple just started now to check against these private APIs.