Hmmm...how would I lose power by doing this? I'm more solid off the floor. If I don't retract and brace strong off the floor my back would be less tight and I'd probably flex off the floor and be pulled out of position? Granted I never really felt this happen to me even when I never really braced as much as I did now though. I just feel it's stronger now.
I think it's a minimal thing for me. It may help someone else more? Remember when you rotate your elbows so that they trace along the bar this will rotate your shoulders forwards. I tell my lifters to brace their shoulders backwards after this. I think it's a better position to pull from.
I tell them to brace backwards so that they don't flex forwards when you break the bar off the floor on the 1st pull and to maintain the back position better. If the shoulders break forwards or are relax and they rotate forwards a bit this will put your 1st pull off. Again this is a very very minimal thing I'd imagine unless it really broke the lifter badly.
Not really getting the analogy
DL would be different as the load is much heavier then a Cn. I think some separation when your trying to not separate would be better hten not making an effort? But for a Dl it wouldn't matter too much, your just concerned with getting the weight up. Not for setting up a really sweet 2nd pull position.