Kirk, I wanted to see if there's any updates wrt PSB files since this thread was last touched. I see they're still not supported, but wanted to find out if your plans (or documentation from Adobe) has changed.
With the large resolution typically available through cameras now, it doesn't take much for file sizes to be larger than the TIF limit. I'm working with Nikon d850/16 bit files regularly, and for some of our commercial clients, 2 gig files are not unusual at all. Factor even a few layers from focus stacking, adjustments and PM is no longer a viable tool, especially when there's the need to see thumbs for comps, etc.
Thanks,
Jerry