If anyone is interested, I did install Ubuntu Budgie 20.04 on a Raspberry Pi 4 4gb. I used the 20.04 Ubuntu Pi image from https://ubuntu.com/download/raspberry-pi, then installed ubuntu-budgie-desktop (and of course made sure to select lightdm during the install). While there are some minor problems, for the most part, it does run pretty well. It does run hot though so I needed to use a fan. The biggest problem I have come across so far is that I can’t figure out how to get tilix to run. It just crashes on startup. I took the easy way out and just installed gnome-terminal instead and set the hotkey to that.
Fullscreen video is choppy, but watching things in windowed mode, like on Youtube or something, its fairly smooth. Not perfect, but certainly very usable. Most of the Budgie applets work as expected. The only ones I have had trouble with so far are Window Shuffler, which doesn’t work right, and pixel saver, which will not install from Budgie Welcome and can’t be found when trying to install it using apt. I just might be doing something wrong here, though.
The only other minor issues I came across so far were with bluetooth and the headphone jack. Bluetooth did not work out of the box, but installing pi-bluetooth fixed this problem. Streaming audio to bluetooth headphones works well, but streaming audio in the other direction from my phone to the Raspberry pi can stutter. The headphone jack does not seem to work, even when there is no HDMI plugged in. There is no way to change this in the Sound settings that I have found, but “amixer cset numid=3 1” at the command line switches audio output to the headphone jack (and “numid=3 2” switches back to HDMI).
I still have to play around with more things, like installing other apps, or multi-monitor setup. But while it might not the fastest Budgie I have used, it is certainly fast enough and works well enough to be completely usable.