in 3.0 stable there is a HiDPI option with text labels in 3.1 this is just a number - how does this number work?
It started out at 4 - but changing it to 8 makes no difference even after restarting godot.
[Linuxmint 18.3 with cinnamon desktop]
If you migrated from 3.0 to 3.1 alpha, you may notice some stray properties in the Editor Settings. This happens when properties are removed or renamed between versions; in this case, the Hidpi Mode property was renamed to Editor Scale, which offers more values. It goes from 75% to 200% in 25% increments and offers a Custom scale mode which accepts any floating-point value.