More specifically, is it harmful?  From the ii-V-I I could backtrack from the I and suss out the flatVImaj7 and the flatIIImaj7, but what about:

ii-up a half step to a dominant -

down a fourth to a maj7 - up a minor third to a dominant -

down a fourth to a maj7 - up a minor third to a dominant -   <-- this is the original V

I