If renaming a manual save to autozsys_(some id) works, the feature request would be to have a zsysctl command that does this for me.
Note that in the example I gave, the save should not be removed yet, as it is one of the three saves the policy says to keep in that time interval, and so gc --all would not remove it either. Removing it manually would be bad because it would leave a large time gap. So I want to say, “I have no special interest in this snapshot anymore, keep it as long as the GC policy says to keep it”.
For “pin”/“promote”, I would only revert in grub if the machine itself had become broken. If instead I messed up something in a project I was working on, I would much rather keep the machine as is, and repair this by hand based on the last known good state. But if that happened near the end of the day I do need to pin the last known good state, so I can work on that tomorrow.