As a side note
Benediction isn't a panick oh shit button, it's a tool like any other. If you spent the whole fight / dungeon not using it then it means you wasted an opportunity to full heal the tank with an ogcd. Same goes for asylum, it is not only for raid DMG (preferably tho)
For instance, if by using it on the first pack of monster it is up for the boss where there are a good opportunity to use it. Just throw it on the first pack to heal the tank, it is good free ogcd heal.

The core idea is to not let your ogcd go to waste. They are not panick button.

Also as a whm you have access to a lot of Regen, let it do it's job.

Many new whm pop a med2 then spam med1, leaving everyone with a Heal over time that will not heal anything because they're already full.

Also, your goal is to be sure people have enough hp to survive the next aoe.

If you know there is around 30s before the next aoe, no need to rush, just pop an asylum, assize or a medica2 and let the hot do its job. And no one needs to be full of the aoe isn't life threatening .

If everyone is at 80% and the ale barely does 40% of the party's health, you're fine, they'll survive

Finally, you'r not a baby sitter.
If someone dies from an attack they were suppose to dodge it's their fault.
Even if healing them prior to the attack could have saved them, it is their fault.
There is a big red aoe marker under their foot, if they can't move it's their issue.

The only thing the shouldn't die from are aoe they can't dodge.