It'd be nice to have an MP dump on healers

[ItMe]

But if you have an MP dump how can the healer be expected to be able to heal or revive when called on?
If healers can turn MP into DPS it shifts the focus of the class a bit too much.
The optimal way to play healers would be for the rest of the team to play near perfectly so you could dump all but the bare minimum MP into DPS... and that would just lead to a lot of friction between players.

I'm also worried about how this would inform how much HP devs would give bosses.
If the healers need to heal a bit more in a run then sorry you don't meet your DPS check. Not to mention this would require a fair bit of coordination between healers to make sure they're not both healing when only one of them can cover something.

Suddenly the game is much tougher towards any mistake and it demands a much higher level of party coordination.
These aren't inherently bad things, but I don't think this is the way to do it.

[Jaelommiss]

The optimal way to play healers would be for the rest of the team to play near perfectly so you could dump all but the bare minimum MP into DPS... and that would just lead to a lot of friction between players.

I'm also worried about how this would inform how much HP devs would give bosses.
If the healers need to heal a bit more in a run then sorry you don't meet your DPS check. Not to mention this would require a fair bit of coordination between healers to make sure they're not both healing when only one of them can cover something.

Suddenly the game is much tougher towards any mistake and it demands a much higher level of party coordination.

All of these are already true for healers trying to minimize their healing GCDs. At the top levels of play every GCD and oGCD is scripted exactly, and someone taking excess damage can be lethal because people aren't topped off and specific instant casts and slidecast timings are used to preposition for mechanics. I suspect that healers who plan fights to that level would be aware they they might need spare MP for unexpected healing and hold ~3k MP until the final moments of a fight. There's little reason to burst to empty at the very start of the fight.

I agree with Risvertasashi that the community would be the biggest issue with these sorts of spells. The response to AST needing Piety to maintain 100% uptime was terrible and I don't see how this would be any different. SE might be able to get away with it if these attacks were part of a complete MP economy overhaul or if they were made prohibitively expensive (1200+ MP) so that no one would think that high usage is possible, but even in those cases I wouldn't be confident in the community's response.