Comment by kla-s

Hey, godspeed to you and your health issues.

Concerning the video/custom mobile-based keyboard: If interested you could look at how kde-connect implements the remote pointer control you mention at the end of the video. kde-connect is also available for macOS, though not fully supported (per https://github.com/KDE/kdeconnect-kde) and the last macOS builds seem to fail (https://binary-factory.kde.org/view/MacOS/job/kdeconnect-kde...). But i can attest that it works great on Ubuntu via GSConnect with Android.