Well, most parts of it since the game cannot read foreign DRM in the community folder.
There’s people fixing aircraft performance etc. without issues, I released a exterior lights mod for the JF Piper Arrow etc.
Main parts of the most complex aspect of the JF Piper Arrow - the panel and autopilot logic - is WebAssembly which is compiled and thus cannot be modded, but that’s fine.
I’m not sure how other companies handle that, but JF has an installer that checks your license upon installation and that’s it.