nvidia 470xx to nouveau ?

Hi: For years I have run Fedora KDE with GeForce GT 710 and the rpmfusion 470xx driver, using VGA and HDMI screens. A few weeks ago, after some kde updates, I started seeing occasional brief pauses and notifications of graphics resets in Kwin. On the Fedora-kde list the suggestions are to change GPU hardware or go to nouveau, with the benefit of a potential switch to Wayland. I have tried to switch to nouveau using the rpmfusion nvidia howto 'Switching between nouveau/nvidia' but my grub menu no longer shows the editable lines quoted. Editing /etc/default/grub instead, or with nvidia and nouveau interchanged, loads nouveau but then unloads it and leaves 470xx running as before. Log after one of the resets is: [ 231.678] (II) NVIDIA(0): Setting mode "HDMI-0: nvidia-auto-select @1360x768 +1680+0 {ViewPortIn=1360x768, ViewPortOut=1360x768+0+0}, VGA-0: nvidia-auto-select @1680x1050 +0+0 {ViewPortIn=1680x1050, ViewPortOut=1680x1050+0+0}" Help appreciated. Also an update of 470xx? Thanks for the earlier history, John P