Hi Elliott,
I have Windows, Mac OSX, and 7610, 705 and 9700 available, along with Icom’s RC-28 controller. Happy to assist if remote access to my gear is helpful.
Additionally, there was a very interesting thread on emulating a RC-28. The thread yields more information about how the mouse driver was made talk to the RC-28 hardware. Especially the bi-directional nature of the button LED’s. The thread author gives hints on how he found the correct approach to talk to the RC-28.
https://www.eevblog.com/forum/rf-microwave/icom-rc-28/25/
My interest in this is in using Icom’s very well designed RC-28 – so I would be in support of creating / testing an open source driver for Icom’s hardware for Mac OSX / linux.
-Karl N7TWP