Astro healing: What to expect?

[Miiu]

All you can do ist trust your healer(no matter the class). But an AST should never wait for the tank or player to drop to dangerous levels just to get the maximum out of ED.
On a personal note depends (on the encounter though) but most of the time ED is used after "unexpected" dmg or hard hitting abilties and the tank dropped to an hp amount I am not comfortable with waiting for benefic II. I pretty much use it like lustrates on SCH except that I can only use it once every 40 seconds.

*edit*

In the end even though I always joke in dungeons when tanks pop "HG / Holm / LD" and "complain" about them having no trust at all, still follow your own instinct. If you think you need to pop Holmgang, use it. Unless its inside raid content where you actually want to save those cooldowns for certain mechanics etc.

[Leiloni]

On a personal note depends (on the encounter though) but most of the time ED is used after "unexpected" dmg or hard hitting abilties and the tank dropped to an hp amount I am not comfortable with waiting for benefic II. I pretty much use it like lustrates on SCH except that I can only use it once every 40 seconds.

This is how I use it as well. You should never let your tank's HP intentionally get low. It's there for emergencies and heavy healing situations. If an AST is slacking on heals and letting the tank get low because they're trying to dps, then they're either lazy or just poor at managing everything. You need to be able to keep the tank at safe levels while dpsing so that will require a bit of stance dancing to continually throw him a heal or two, maybe refreshing Aspected Benefic, before going back to dps.

The only healer that can get away with staying in Cleric for long periods is SCH because they have the fairy, but even then if more damage is going out, they may find themselves popping out for an Adlo or something. So it's really not just an AST thing. Any healer that is letting you get that low is not playing correctly.

I've seen the excuse that they want to optimize their class by outputting dps but the reality is if you want to get the most out of your class you need to do both well - healing and damage. That requires more effort on any healer, but letting the tank get low is just a bad (and as you can see from the OP's concerns, also inconsiderate) idea no matter how you swing it.

ED is there for unintended situations and it's great for that. As Miiu mentioned, it can be compared to a Lustrate or a Tetra.