Well, I'm fine with AST mana right now as it is... Basically I ALWAYS align Lucid and Celestial opposition, sometimes I will use Lightspeed extended too.
AST has so many tools to make mana economy (Synastry, Earthly Star, Dignity, Buff extension on regens...) and in extreme cases of raising you have that RNG Ewer that can pop and save you. And then yeah sometimes you have Refresh or Mana Shift (or someone else raising).
AST is fine as it is I think. The latest QoL changes were more than welcome, and there is nothing that comes to my mind that could do with some minor fixes.
(apart from making the spear OP by raising the Crit stat and not chances of Crit, but I'll never see it haha)