I think it's mostly buggy when using an external monitor with a different DPI (internal 4k with an external 1080p, in my case). With the environment flag, it w

I think it's mostly buggy when using an external monitor with a different DPI (internal 4k with an external 1080p, in my case). With the environment flag, it works pretty well. On Gnome, plugins can cause issues. hidetopbar, for example, had an issue with Firefox when the screens are stacked vertically.