Apparently GNOME supports it:
- Enabling Variable Refresh Rate in Gnome 47
- Fedora Variable Refresh Rate - Linux - Framework Community
gsettings set org.gnome.mutter experimental-features "['variable-refresh-rate']"
If it needs to be Xorg, you need these packages on F41 Workstation:
gnome-session-xsession xorg-x11-drivers setxkbmap xhost xmodmap xorg-x11-xauth xorg-x11-xinit xrdb