If you spot vandalism in OSMCha, or if you goofed up on one of your changesets, you no longer need to fire up JOSM to revert the changeset. ohm-revert is a new variant of osm-revert tailored to OpenHistoricalMap:
Just enter the changeset IDs to revert, along with your reason for reverting them. ohm-revert will take care of cleanly undoing the changes, resolving conflicts, and notifying the author of the reverted changesets.
As with any reverting tool, make sure the changeset is in fact irredeemable before reverting it. Often, manually undoing a change is less risky and less likely to create friction between you and the change’s author. Use your judgment when undoing others’ work.
Thanks to @NorthCrab for whipping up this tool in no time!