For a long time the doctors said I had a enlarged prostate. It never bothered me. My PSA is always very low and the feel of my prostate didn't signal anything bad to ever get a biopsy.

I'd just assume that once you are over any pain and any healing the biopsy requires, that your current saddle will still be good enough if you were okay with it prior.

Your prostate didn't just suddenly enlarge. And if you are having some issues, then maybe they are other things. Such as hemorrhoids that flare up from the pedaling and other reasons.