Well, I can report that it works

Without any extra extensions or controlpanels...

The suspicious "thumb button" on the side, turned out to connect the mouse to the tranciever.

Duplicating the tranciever board, put it inside the Plus chassis, and plug the db-9 connector at the back would make a cool hack.

Even better would be to move the mouse internals to a Plus "brick" mpouse, and cut the cord.. :beige: