This seems interesting. Do you know of an example of a pro bodybuilder who turned to powerlifting? I wonder how their total muscle mass would change/redistribute.
There are plenty of examples of bodybuilders who also took powerlifting movements quite seriously. For example, here's Ronnie Coleman deadlifting 800lb: https://www.youtube.com/watch?v=uYm7SJn_6ZI
An "edge" IMO is something that gets you a 1% advantage ... maybe ... at the top end of competition.
The problematic aspects if PEDs isn't that they are a minor advantage. A 10% advantage in top athletics is game over for non-PED users.
Steroids are mostly equivalent to EPO in terms of advantage it provides to top end competition: as in there isn't one. If the next 1000 athletes in ability dope with steroids (fast twitch) or EPO (slow twitch) but the top naturally gifted athlete doesn't, guess what rank he'll be in the world? Probably in the 100-200 range, fighting to barely stay in the top pro ranks.
If the PED gives your competitors a 20% advantage? Maybe you're an ok starter in Division 1 NCAA or a second-tier pro league.