I never had an issue to simple choose in Gef.Experiance the install-button. In worst case I download new installer from nvidia direct and install it, allways also direct with Gef.Exp. .
Only thing I do is choose manual install , because I not want the hd-audio drivers.
In case I want to do a “reset” I additional choose the mentioned checkbox “completely new install…”. Nothing else was ever necessary.
Gef.Exp. user should allways aware to disable game-auto-optimization in Gef.Exp. settings.
In case users not need features of Gef.Exp. they can also install it to get e.g. the update notifications / easy installer. All of the other features , also and in special the overlay, can be disabled.