I've lamented over this same issue. I have a number of limbs and I bought several that are No. 1s. I have a 30" draw with a 2r grip. And I've had several sets that no longer have good cast, probably due to overdrawing (but not by me). All of these were #1s except a set of 52lb #2s.
Last weekend I went out and checked all of my #1s with both an A and B riser that I still own. I much prefer to shoot an A riser as they are much lighter. But I worry that I might be doing damage to the shorter limbs. Unfortunately my B mag riser seems to have fitting problems with most of my Grayling limbs, which is real surprising to me but a different issue. The best that I can tell I didn't see any real stacking on the three sets that I had out there with the A riser; red tip 42lb, red tip 50lb, blue tip 60lb, all #1. I shoot pretty heavy arrows and I think that alone will stop damage at least up to 30.5 or so. On the 50@28 I shot a full length 32.5 340 with 300 grains up front. Just for comparison my 49@28 60" SAIII shoots a 31 to 31 1/4 340 with 300 grains up front.
Next I'm going to just simply take the stuff down to the local indoor and check the limbs on a scale and really see if there is any stacking at all to 30 and where they really do start to stack.
But just to be safe, shoot heavy arrows.