Having the same issue in my VM… it really is tied to the scale… the moment I drop it back to 1 after being on 2 the CPU levels out to a more reasonable 10-20%
Issue still exists now, fresh install of Ubuntu Budgie goes from 10% of CPU usage on 100% up to about 35% when set to 200%
My laptop’s screen is 4k so this kind of performance hit has forced me to swap from Budgie, which is a shame as it’s a very pretty DE
While impossible to confirm now I did not have this issue on the previous installation on this laptop, which was an Ubuntu default installation with Budgie installed later - which I note here if only to help somebody else going down this rabbit hole in the future