You can't mock it, that is the entire point. Simply loading the shared library of the SDK will execute the broken code.

90% of people in this thread think “native code” is a react plugin

I don't, but I'm fairly sure there is a solution and others just don't want to try hard enough

Can validate, no reasonable way.

Removed the SDK myself from a top 100 App Store app.

So an app (which you control), is told to load a shared library, and there's no way to handle that? Even by delaying the loading to only when it'll be used?

It's not "is told", it is "it is writen in the binary itself that the kernel/libc runtime should load the shared library".

To be fair, you don't have to do it that way. (Library loading is done by dyld, FWIW.)