I spent a couple of years doing basically a 2 day rotation, and a couple of years doing basically a 3 day rotation -- two different programs.
In the 2 day setup the gross room was also the frozen room, and also had a full time very very good pathology assistant who was capable of handling the entire grossing load alone. On day 1 we would gross and handle frozens if the attendings didn't sneak in and do it themselves; the group was private and still had a sense of treating surgeons as personal clients (also a big part of the reason we had a 2 day rotation as they wanted as fast a turnaround time as possible). Slides would start to become available about 6 AM on day 2 but most of the attendings wanted to start signing out by about 9 AM, so preview time was often quite limited. Unfortunately as that program only got ~50 autopsies per year we mostly did them on a rotation (other variables came into play so pretty much those on AP rotations or just SP did them, but not worth trying to detail all that), so you could lose out either grossing or signout days pretty easily. The worst part was the difficulty in getting decent preview time; we tried various things to work around this, such as starting signout later or previewing half while the attending signed out half, then swapping, then briefly flying through all of them together at the end of the day, but it never seemed to work out particularly well as a system.
The 3 day setup was at a more traditional academic program. The gross room was separate from the frozen room. On day 1 we grossed, focusing primarily on the larger/excision specimens and usually letting a PA or PA student handle popping biopsies into cassettes. On day 2 we did frozens and read out biopsies from the previous day (so, biopsies from our grossing day but probably NOT grossed by us), which usually finished in the early to mid afternoon; most days we were able to preview biopsies in the morning, and finish biopsy sign out by early afternoon, unless there were a lot of frozens -- but for better or worse, most days did not require a lot of time on frozens. In mid to late afternoon the slides from day 1 grossing were out or coming out so we could begin previewing; we had until the start of sign-out the following day to preview, do initial dictations, etc. On day 3 we would start sign-out often between around 9-10 AM with the attending. The case load was such that some days were busy, but enough days were sparse enough to find a window to follow up on special/immuno stain cases, intradepartmental consults, recuts, going back to the gross bucket, etc. so everything could be completed in a reasonable timeframe while still having some time to preview and read. There were occasional long days, usually those who preferred to stay late and preview rather than come in early, but "late" still meant 7-8 PM, not 11 PM, and many senior/efficient residents were regularly out before that. The down side in terms of competing with a private group was primarily turnaround time, but it worked much, much better for a training program IMO. It might have been able to work by grossing on day 1, preview & sign-out big specimens on day 2, then frozens and sign-out biopsies you didn't gross on day 3 -- I seem to recall it being discussed but, frankly, it's all a blur now.