I would also try to completely redesign how mobile builds work in Unity. Instead of Unity creating a brand new xcode / android studio project every build - it should be able to take an existing xcode / android studio project and just add the Unity build to it. That way, theres no more stupid post-process steps that inject all your native code plugins into your xcode project. This step is super fragile and constantly breaks. You can keep your xcode project updated manually and the mobile plugins would no longer need to develop their unity build pipeline.