I've been using Xfce on hidpi since 2015 with just font scaling (using the DPI setting in xfce4 settings/Xorg), and it has worked fine, other than the minor iss

I've been using Xfce on hidpi since 2015 with just font scaling (using the DPI setting in xfce4 settings/Xorg), and it has worked fine, other than the minor issue of unscaled icons in the Window Buttons panel.