@FakeShemp I get what you're trying to ask
You're saying you usually need more dope than usual to break thru subs.
You're saying that fent breaks thru the subs (which yes, similar binding affinities)
But the next part -- you're asking if you do fent (theoretically knocking the bupe off receptors and replacing with fent) and then some time later do dope would you still need more like you do when you do dope while.on subs?
Well, first thing-- it depends. Fent and bupe have similar binding affinities so if dope can't replace the bupe in lower doses it most likely won't replace the fent
But-- with bupe being a partial agonist and antagonist it's mechanism of action is different.
So if you do fent for a few days and let the bupe lower in your system, you'll likely feel dope better because it synergizes with the fent(both being full agonist)
Warning tho -- if you intend to go back to subs, always keep some in your system. It prevents the pain of pwd when going back. As long as I have some sub in system I didn't have an issue going back on. And because fent stays in your system very long (lipophilic) it's hard to go from fent to bupe. So don't set yourself up for a world of hurt. Take even a low dose of sub while you're playing around. You'll save yourself some agony