Quote Originally Posted by Evergrey View Post
if you can come up with a Shield rotation that matches a boss's attack pattern so that no shield would be cast when not really needed be (aka, Overhealing), do share it.
But this is exactly how endgame healing works in general. Encounters are scripted, so people solve them by developing mitigation timelines to match boss mechanics timelines. Hell, ultimate PF discords even have mitigation sheets posted in their strat sections.

And shielding is not even needed in this game for a lot of the raidwides, because it all comes down to GCD efficiency and such, so if party cannot be killed by raidwide and will be topped up with oGCD regen or such before next one then this is what is used.