Basically, this skill is meant to extend your Greased Lightning timer to maximum after you take damage. Therefore, this could be used on phase transitions in raid fights where you take damage when the boss jumps.
Except, it doesn't work like that.
If you receive a shield from a healer, or any mitigation from a tank and don't take a hit to your HP, this skill doesn't go off.
This means, I am clicking off succors and adlos, trying to dodge paladin wings so I don't lose my stacks on a transition.
This was such an issue in UCOB in the Twintania to Nael transition as well as Bahamut trios (before the Perfect Balance changes) that my entire rotation would change based on whether or not I got a crit adlo. It was so frustrating I just switched to ninja and finished UCOB as a nin.
The transition from Ifrit to Titan in Ultimate Ultima I have the exact same issue. I have to position myself perfectly on the edge, enough so I don't die but also a little further forward so I can go into titan with Greased Lightning stacks.
Outside of raid, the only way to use this in casual content is to run ahead of tanks, pull mobs and stand in their attacks.
I don't believe this skill is working as intended.
TLDR if healers/tanks perform their jobs correctly, Monks dps rotation suffers.