Technically, yes. If you open your Unleashed config file you should see a folder for each of the mods in DW20, Unhinged and Unleashed. You should be able to mix and match by putting GT or DimDoors in Unleashed. However you cannot pull mods from DW20 or Unleashed into Unhinged and have them work. Unhinged has different Id's.
I won't lie, I was just talking today with a friend about all the cool little mods unleashed had that I wish we could use in the direwolf pack. we'd prefer to work with unleashed but his computer just can't handle it for some reason but runs fine with direwolf. This new revelation has made the heartache of a lost world much more bearable and worthwhile! all the little mods ftw! thanks guys, doin a good job