Though the enmity issue is (should be) resolved with ShB, the syncked vs unsyncked DPS balance is not.

Someone with their full action set available needs to have their damage scaled down so that they don't hit so hard that things melt while an unsyncked DD is unable to perform more than a few basic actions. Then once this is implemented, it leaves a new problem in that syncked people will need to be as good as they should be for their real level, even when they're syncked down. If they are not, then they will do less damage than unsyncked people.

Giving everyone all their unlocked actions even when syncked might make things more interesting for the higher level people syncking down, but it would overall make dungeons slower, as many people are not as good as they should be for their real level. The way things are now, a decent run time only requires people to be as good as they should be for the dungeon's level.