I have read on other forums that the 17 G3 works fine with the gtx 980m and the 1060m as well. I think those wont work with catalina, thought...
I have a 17 G3 and for some time I had mojave running fine with the quadro disabled...That way the system was really stable
Mine is a 840 G5, not 830. Earlier in this thread I have posted PR files that you may take a look. The trackpad works, the cursor is a little jumpy sometimes, but overall its fine.
Did you get sound working?
Try switching to i2c branch and use elitebook G4 files. I have an elite book G5 on 10.14.2 and camera, audio and trackpad are working fine. I have some posts earlier in this thread with PR files that you may want to check.