Version rolling is not possible with most (stratum V1) pools; the ticket send back to the pool does not include nversion. ntime is no problem though, but you 'only' gain 60x with that, so you will only have to send work to a single asic @250GHs once for every work from the pool, or even @500GHs on ck's pool (as the work time is now reduced from 60s to 30s). Some sort of block generation will be unavoidable sooner or later unless they do something with the serial interface to make it fast enough (a normal T17 needs a ~1.5Mbaud  connection between the asics, to a S19j @120GHs would need roughly 3 times that speed without block generation).