I'm kind of impartial to the phase transitions.

On one hand, it does get irritating from time to time. I agree it would streamline the EX trials faster and make farming them smoother.

On the other hand, it helps me recover my cooldowns and what not. I also have enough time to farm all of the Stormblood EX primal mounts ironically enough (all 3 of my main characters have the Kamuy of the Nine Tails mount).

So it's going to be a coin toss for me should the long intermission phases occur again in the next set of EX primals going forward in Shadowbringers.