I think smaller pockets would make a difference in two major ways other than just rejecting marginal shots. To be more accurate, I think Jayson would have to slow down, and with less pocket to use, moving the cue ball and bumping balls would be harder.
As for what sort of run we might expect, Filler ran 285 on 4 1/2 pockets while Orcullo ran 260 on 4 1/4 at the last DCC 14.1. I don't think either one had more than 20 tries. In the right situation, I think we could see 527 if those two and Jayson and a couple of others were trying on half a dozen tables for a week. I think 800 is very unlikely, but then I thought that we would never see 200 at DCC, and it became standard in later years.