Is the 0-Click Ban also extended to the first coil of bahamut?

[ispano]

Does the ADS work the same way whether you're currently still struggling with minor bosses or only if you've already engaged him?

If ADS works the same way everywhere you are, no exploit was made.
If ADS only works that way when you've already engaged him, I still don't see any problem.

They are very capable at making one-shot enrages. Perhaps they didn't intend people to deal with it that way, but there was literally no "underhanded exploit" made, so they couldn't really change it without raising some questions.

I never said exploit. I said it wasn't likely intended, like you just said they didn't expect people to bypass all the other mechanics and just brute force heal through the enrage. Doesn't have to be an exploit to be unintended.