Maybe my M1 doesn't know about that limitation, because it sure did work for me, all week. ? In every scenario I used the Mac, the charge never went past 80%. Otherwise the computer behaved normally, clamshell and all. Would that not fulfill your "it works" criteria? Any guesses as to why it did work if it shouldn't?
But on Friday the Mac stopped waking up, unless the charge was below 80%, when in clamshell mode. Had to keep the lid open, which is kind of a bummer, because I use and hold very dear my vertical Brydge/Henge dock. (The misbehavior was the same even without the dock, I tested that too.)
The only variable I can think of is 12.2.2. Everything else remained the same, as far as I know. And that's a different kind of "does not work". Affects not just charging, but the whole Mac, so unfortunately I had to uninstall AlDente for now.