Yea it's totally fine in comp IIRC, just won't get the start command until you're all set tight again takes stress off the shoulders as well!
Ahh that's cool. I'm going to have to practice it more, as I lose some tightness is my back afterwards, it's not really an issue in the lighter sets, but as I get into the heavier sets the loss of tightness feels like I'm working harder than I need to or should be.
I can definitely feel the difference it makes to shoulder stress too.