Andrew - as noted, the sensitivity settings (gain etc) are adjustable in the G600 and required to be adjusted for normal operations or the FD can be “hyperactive” and prone to oscillations. It’s outside the install manual and the single biggest 2100 issue I see.
That said, I flew yours for a couple hours left seat and another 4 with you and didn’t note any issue but also did not hand fly in chop so it sounds like that might be the issue. We have those settings available. I also spent many hours in mineral wells back in the day after certification trying to modify and make it fly as good as possible but there’s a reason there’s a 3100 now. I just bought one. I hope they fixed the YD as well.