Turtacular
No, downgraded is probably not the right term.
After the GOS updates that restored RCS functionality, I initially was able to connect, but then RCS stopped working after 24-36 hours, similar to the pattern several others have experienced. I followed the advice of upthread @vuraze provided (post 1223) , and disabled RCS, uninstalled messages, rebooted, and then installed 20241120_00_RC07 cleanly. RCS immediately connected for me, and has remained connected and functional since.
I believe my situation is similar to @Pixelated, albeit on different versions of Messages, and wanted to provide my datapoint.