The Doctor's Mobile emitter wasn't and that was centuries ahead of it's time.
Did it solve more problems than it created?
Cross time Braxtons and Ducanes are not struggling to make their own home more real than other timelines pushing through and crushing their concept of reality, otherwise the "integration technology" wouldn't be used to fuse together temporal doppelgangers in much the same way as Neelix and Tuvok combine their entities to become Tuvix... I wonder if it was decided by someone with presupposed moral superiority decided that the several Kathryn Janeways and Anika Hansen's who were mashed together after the episode "Relativity" should all be split again since they're all vital people who deserve their own lives even if Voyager wasn't roomy enough for the lot of them, especially if 5 kathryn Janeways simultaneously and equally start insisting that it is they who are more real and deserve command of the ship and god help anyone who gets in her way or sides against her...
So Braxton (or Daniels be serving from outside time, like Annorax was) probably has a "bugger it, close enough" rule of thumb (t)he(y) subscribes to before (t)he(y) submits him/themself and thir crew to integration with whatever doppelgangers are wandering about in the new shape of time thinking they are the original and definitive Braxton, his crew, others, et all... Although we know the process eventually drives you space crazy.