Yup, I have this too ever since UDL was last updated, and I don't even use UDL yet. A plain empty map only climbs to a certain point and then stabilized, but any map with ANY kind of LD + Light,,, and the memory will not just climb a bit (which would be reasonable), but it will also not stop climbing, at all, until I move to another page. And when I move to another page, it doesn't release that usage either... So if the firefox.exe process that runs the roll20 window is at, let's sat 700mb... and stable.... then i move to a more populated map, which BEFORE the recent UDL update brought it up to like 3gb... and then stable... Not anymore, it'll climb above 3gb, and keep climbing... and let's say it climbs to 11gb.... so I move back to an empty map... Sure it stops climbing.... but it also stays at 11gb... until i either Exit Game, close the tab, or kill the process. Before the update... it only climbed up until it had what it needed, and got stable there, and when moving to less intensive maps, it released the ram, and sank down to what it needed instead of staying at the grown value. Stupid, and I've had to kill the process on the other computer where i run the player account on like 5 times today... which btw grind the computer to an almost halt so it takes like 20 minutes just to kill firefox.. I wrote about it in the official UDL bug post as well.
