AST only has 4 OGCD heals, Essential Dignity (40s CD), Collective Unconcious (2m CD, might as well have a cast time since it takes about that long to register, also channeled), and Earthly Star (1m CD, but starts before detonation oddly, takes 10s to full power detonates at 20s regardless if its useful then, can "miss" if tanks/dps move and dont consider returning, and can be delayed 10s if one uses Celestial Opposition, and the delay is current state time added i.e. Oops 20s buildup). Last would be The Lady which is behind 3 layers of RNG and choices, Minor Arcana is a 5s CD with a 50% proc ratio that works off of a 30s with a 16.6% proc ratio which is also used used to assign 2 arguably more important functions than an OGCD heal, which after all is said and done has a potential to have between a 20s and 2min CD for a weaker than even Bene 2 heal (2m max CD being 2 uses of Sleeve Draw and 1 giving The Lady, 20s min being, Minor Arcanaing 2 Draws, and getting Lady out of Sleeve Draw. Could get a 4th with enhanced spear on self, but really?), but in practice could never show up for an entire dungeon or raid.
I agree adlo and succor cost too much MP. ABene was hit by MP cost increases as well, but alas it wasnt the most expensive single target heal in the game as adlo already was and still is, WHM regen escaped this hit somehow. IIRC Adloquium is 300pot heal with = shield that doubles on crits which would make it 600pot base with 900xcrit multiplier pot when critting. ABene is a 200pot heal with 250% shield (~230 pot after noct sect bonus) 705 base (230x2.5=575, 575+230=805) with just the crit multiplier to increase it further. Technically it is stronger non crit. I know crits potency was reduced due to direct hit/direct crit being added, so assuming its in the ballpark of 175% now as opposed to 200% thatd make them cap out at roulghly... (300x1.75=525, 525x2=1050, 525+1050=1575 for Adloq) (230x1.75=402.5, 402.5x2.5=1006.25, 402.5+1006.25=1408.75 for Noct ABene) Not enough for the cost difference but it is weaker on crit. Just for reference at 200% multiplier this would drop to 690 base/1207.5 Crit for Noct ABene.