I do recall installing both throughout the day. The failure happened immediately after the second. I’ll try your other recommendation tomorrow, with a live USB. Thanks
UPDATE: I’m finally back in! I’m glad I didn’t go RJ Macready vs Chess Wizard on my comp! I’m glad this CPU features an iGPU, switching to it, I was able to get to a login screen with DisplayPort, it was solid black after logging in. Switched to HDMI, logged in…black screen with a pointer, force shut down again…switched to X11 (had been attempting Wayland), got in! I ran the microcode, firmware updates, shut down and set up hardware as it was, hoping for the best, selected Wayland (I’m on Plasma 5.27.7—sorry my posts were extra useless since I’d no access to my login), got back to my beautiful desktop. Happy tears.