On one hand, I don't see why giving players a buff to select when to yeet to the stooge that gave it to you is such a bad thing. It offers what OP wants: consent, it's less intrusive and it places the responsability 100% on the person for clicking it too late\early\not at all rather than on the healer for using it at all.

We have two duty action buttons as it is, it's not like repurposing one is going to break anything. Plus, could even allow for more actions of the sort.

On the other hand, it does defy the purpose of Rescue. Often, healers rescue you specifically because they see you screw up and you WON'T have the mindset\knowledge of the mechanic\reaction time to correct it. So sometimes giving up a bit of control is good for you not wasting them 2400 MP and some sanity. And some DPS for the whole party.

"Just leave me dead" is all fun and games until you realize this could save entire parties if the next mechanic requires specific people to be alive.