Not saying it’s likely to help with the trackpad issue but 3.05 is the current production version:
That aside, is there any chance of bad grounding (for the whole laptop/power supply) or static buildup?
Just going from first principles more than anything else. I haven’t encountered this (FW13 7840U since late 2023) but then again most of the time it’s docked and using a mouse instead of the touchpad.