I solved this problem a few years ago by keeping an old iPhone velcroed to the mount, acting as an intermediary with the iPad. A clumsy workaround, but it worked. My comments and brief tutorial are somewhere in your archive.
Just looked in today and found all the work that you’ve been doing, so I decided to give it a try.
Connected iPad to Mount using “Scope Type: Skywatcher SynScan Link” and it’s up and running first time. Wow, great work people, thank you very much for pursuing this.