I built a test package that was tested by Edu with his Driving Force GT wheel. We discovered a few issues that I was able to fix.
Since the DFGT wheel supports adjusting the wheel range, I decided to add support for the wheel range change command (which is an extended command in the Logitech protocol). I also added support for the set rpm leds command.
I have a g27 built a DIY USB and want to help in testing. I can help in bug fix .
I sent a mail to the address you provided when writing this comment.