before a downtine is always a win too. (not necearlly better than on the opener but still, if you're unsure)
You have downtime on Chaos before orb and wind jump (by altough windjump is a very minor downtime)
Mygdra has plenty of downtime with add phase transition, after the tailburn thingy too.
OS11 has 2 downtime, one before TV and one at the end of TV, however I would personally not waste that on the TV...
OS12 has a few downtime during the goo split and electric slides.

You can also do it if you see you've just failed a mechanic and are about to die
Considering the time for you to be rezzed, resummon turret (which will deal 25% less dmg), that's definitely a win