I recently used the latest EndeavourOS ISO to install Gnome on my ThinkPad X1 Extreme 2, which has a NVIDIA GTX 1650 Mobile dGPU. I managed to get fractional scaling working under Xorg.
To enable fractional scaling on X11, we need to install these 2 packages:
mutter-x11-scaling
gnome-control-center-x11-scaling
But gdm and chrome-gnome-shell prevented the installation. So I had to remove them. After that the installation proceeded successfully.
Finally I installed back gdm and chrome-gnome-shell (less important and can be done separately). After reboot, fractional scaling works very smoothly on my external monitor.
No problem. I looked into it as this is my first Thinkpad with a WQHD screen. I tend a dual monitor configuration so this is handy.
I kind of wonder why its experimental. Seems to be a priority for the community to test. Would be nice to have the option to turn these on in gnone tweaks (or extension) as Gnome likes us running in production with extensions vs incorporating the feature