They need to revert it, cast times most importantly.

If they want to give blm more room and less chances to mess up, Give black mage a spammable movement option that's a slight damage loss but resets the timer for emergency situations where you need to move or if you mess up astral fire timers.

I'd also remove Astral Gauge this gauge has caused so many issues with how black mage is designed, they can either make flare star a upgrade or be a follow up attack from despair (either one is fine) I personally resent this gauge as I think it's a key reason why people have been complaining about DT BLM and hence we got this bad rework.