Hey Ed,
No issues with TRR. It's been my experience that in competition, you are more likely to do the TRB, because the course of fire and fate make it work out that way.
However, it is not outside the realm of possibility that you would complete the necessary hits at one shooting position, but experience a malf' that you would want to clear BEFORE setting up at the next window, barricade, etc.
TRB-or-R as is needed is important and you're right, you won't always need to go bang immediately, but many times you will.
Stay safe,
CZ52'