Thanks much for your hard work.
The update script worked flawlessly. Because I had putzed with compiling my own kernel, when I booted for the update, I selected an earlier distro 5.10.0 one, and kept my fingers crossed.
Chug, chug... the upgrade script chugged away for an hour. I worried I might have broken dependencies. I did the sudo apt autoremove bit when it said it wanted to reboot before rebooting and...
Success! Everything I use on a daily basis seems great, and I'm burrowing into the stuff I use once in a while.
No complaints, though, and many thanks!