Update 1: I read TN3125. I decoded the DER-encoded version of the embedded.provisionprofile. The SHA-256 hashes of the two Developer Certificates match the SHA-256 fingerprints in the developer certificates installed on my iPad. Update 2: The Info.plist files that are embedded for both the App and the DEXT are a mess. After using plutil to clean them up, the are now readable again. The source Info.plist files look fine. When I run plutil on them, they look the same as before I ran it.

Update 3: It still won't install, for the same reasons.

Update 4: Using Automatic signing and "Apple Developer" vs my personal developer certificate also won't load.

@BenjaminApple , IOUSBHost seems to be a part of Driver kit (i.e. also exists in iPadOS on an M processor). Is there something I can read that will explain how USB access should work on iPadOS ? I think I also read that the driver kit includes portions of IOKit and this has me further confused as to what should work and what should not work. Thanks for helping me steer through this!