I'm in favour of scrapping it in favour of unique mp recovery, its yet another avenue to undo homogenisation and fix healers
unlike most posters im in favour of mp management being something to learn. At minimum, the basic attack (glare/broil/malefic/dosis) should all cost 0 mp to encourage a freshly raised healer to do something productive while lucid is coming off cd. Basic competence is managing your mp, this is hammered home in the conjurer questline. Smart play shoudl allow mp positive and enhanced gameplay
Lucid can be returned to whm as shroud of saints at level 24 and have it get a trait at later levels where it instantly generates a lily or it can consume a lily to generate double mp. Right now whm overcaps lillies in some duties because there is so little damage and the gcd is better spent on refreshing dia and dropping an ogcd heal and struggles with mp between cure 2 and getting lucid since cure 1 is tapering off in usefulness but cure 2 is expensive.
For sch, i concur with selene having an mp restore, and her other ability should be a silence fitting the "Eos to sooth and salve, Selene to Support and Silence" bit of sch's lore that forms the core of the fairies.
As for astro, well this was one of the strong points of the unique cards- despite what parsers like to pander around the ewer was a great card. it could give yourself a decent recovery of mp, the rdm get back on their feet or back into the game after a verraise and you could always burn it for an aoe card later. Not to mention slapping the bole on the tank meant you didn't need to use as much healing on them indirectly saving mp.
It also had another ability called luminiferous aether. Lucid dreaming but with an enmity reducer, very helpful for your tank. Them scrapping LA and then the Ewer was what caused launch ast to be as bad as rdm when it came to bleeding mana.
Astrodyne is already having an mp restore every time you trigger it come 6.0 plus the excellent draw-gain 800mp
LA replacing lucid dreaming. How about grants the effect of noct sect for the duration of its mp restore- give back more access to the shields that were unneccessarily stripped from it for a pure/barrier split that doesn't actually exist. Alternatively have it consume a card drawn or astrodyne seal. Either of those can directly allow smart play to get the full 3 seals.
Sage can easily have an mp steal attached to any of its attacks.