To some degree there is a misunderstanding with regard to the use of small base dies.
Largely, the intended use of a SB sizing die is for sizing brass that will be used in multiple different semi auto's such as an AR15. Or, if you are using range or surplus brass. Under those circumstances some will opt for a SB die to ensure reliable feeding and extraction, for every round fired, in all guns, using ammo loaded with those cases. Some will also use a SB die with new brass or their own once fired brass if they're shooting the same ammo in different guns.
A small base die is a FL die that sizes the base about 1 thou smaller than a standard FL die, some may be capable of pushing the shoulder back a little further than a standard FL die as well.
For all intensive purposes, if you're starting with new brass or new factory ammo that will only be shot in the same gun every time and you are, correctly, adjusting your sizing die, you really shouldn't ever need a SB die. If you're using a SB die under these circumstances you're just over working the brass and likely costing yourself a little bit of accuracy. The biggest concern with over working the brass isn't so much shorter case life or even the accuracy part but it can potentially lead to case head separation and a ruptured case will surely ruin your day.