I've thought about adding that. The furthest I've gotten was 99; felt like a slap in the face for not making 100. Unfortunately SRC really only allows timed runs rather than most points as far as I know. If not, let me know. However I'd be happy to put in some categories for number of floors/rooms. They'd be under the Misc. category most likely.
I and a few others feel that having alternate categories for lower difficulties would greatly increase interest in running the game. It would even have a higher chance of appearing in GDQ since the lower difficulties are more consistent. Upon getting more interest in running the game, runners will likely look at doing Master runs. I do realize that currently there aren't enough runners to care, however I do strongly believe lower difficulty runs will increase the runner-base.
Would lower difficulties be accepted? As in possibly a separate category. I feel that's where the difference between any% and all dungeons would really show.