I ride with my saddle all the way back on a set-back seatpost. Ignore KOPS and go by comfort. Putting your saddle further back slightly changes muscle recruitment so it takes a while to get used to, but in the long run it's fine. I don't think a smaller bike would change anything much for you since with the saddle the same height and the seatpost probably at the same angle, your position w/r to BB would be the same.