I don't have a strong opene yet, but this is how i handle the new Transe mechanic.

I use a 1 min rotation where i start with 0 Aether Flow, 3 bahamut stacks, Aether flow spell available.
I try to always get 3 aether flows during transe to maximise fester + delaing the last one to get Transe available in same time than Aether Flow

0s : Aether flow -> 3 flows
0s : Transe
0s: Fester (1 bahamut stack)
(it might have some few delay in the real game)
10s : Fester (2 bahamut stacks)
40s : Fester (3 bahamut stack, Transe available for the next 30 sec)
60s : Aether fow avaiable, transe available too,
0s: new rotation

This ensures to have 2 festers with 330 power.
Tri disaster would probably be user during transe at beginning or ends (but always at the same moment on each rotation) in order to always have the same order when reapplying dots.
Ruin 1/2/3 as filler as usuall