What does flying a retract have to do with it vs down and welded? I don't know anyone whose habit is to put the gear down after passing the numbers on downwind, and I certainly don't do it that way. Anyway I agree, you should not be bound to a particular routine, but that's completely orthogonal to the question of which is the better SOP when flying the pattern, "stabilized power on" vs "power to idle abeam the numbers". Regardless of what your SOP is, you always need to be flexible and capable of adjusting for other traffic, obstacles, ATC instructions for whatever reason, etc. I'm just agreeing with the earlier poster that building a very intimate familiarity with the power off part of the performance envelope in order to be better prepared for the possibility of engine out for real is a good argument for "power off abeam the numbers" as SOP.