I have been using Firefox on a Linux server, so that Firefox either is piped to my Windows computers over SSH to a Cygwin/X server, or I am using X2Go client. Both ways have worked perfectly until a while ago.
A few updates ago Firefox turned very very sluggish. It sometimes tooks tens of seconds for a page to respond to button presses or my tries to scroll a page. Even Firefoxes own UI became unresponsive, like pressing the hamburger button took sometimes over 10 seconds to open up the menu.
I managed to track down the problem to something called webrender, and when I turned that off (about:config -> gfx.webrender.force-disabled to true, and in regular settings turn off hardware acceleration), everything started working perfectly again.
Now in this recent update (92.0.1) everything turned very very slow again. After some work I found out that in about:config turning gfx.webrender.force-legacy-layers to true makes everything good again. The force-disabled option was still true, but looks like it didn’t have any effect.
Is this a problem I’m gonna be having? Is this “webrender” something that’s gonna be forced on every user? Are the “legacy layers” gonna be taken away at some point? If so, is there anything I can do to make the webrender usable?