I'm not aware of any plugins for better conflict resolution.
The changeset size makes it hard to find all the issues especially since OSMCha and Achavi can't load it.
I've only been using https://osmose.openstreetmap.fr/en/map/#loc=7/55.776/11.71&level=1%2C2%2C3&item=1210&class=3 but it doesn't find all disconnections.