...Are you actually spending time grinding away the actual base that is part of the figure?
I do, though it sounds like lots of work...but it isn't.
Slotta tabs - either remove and use pins, or simply cut and file the slotta tab into "pins."
Integral bases, bit more work, but not loads.
The time, for me, is relative. If, as I often do, make up my own scenic bases the time is actually slightly more than if I use a "ready-made" and remove integral. (Check my website for all types of bases on figures.)