Wonder for interactivity of AoEs in general if they could add a new concept of sweet spots, conditional distances, with more of the smart casting of MOBA games.
For example the Art of War AoE might have a concentric circle (smaller than the normal aoe range) that does additional bonus damage, if you press and hold the skill you can see the aoe underneath your feet (and it actively updates visually as you move around so you could aim it if you wanted) but tapping does as usual and just casts the skill.
Maybe Samurai's dash skill (Hissatsu: Gyoten) has a linear aoe marker with a two small squares in the line, where the first is where the monster is meant to be and the second where you'd appear. If you do it at too short or too far you'll just dash to the monster, yet if you line it up you'll dash through the monster (that classic Samurai slides through attack) and deal some bonus damage. The skill as a courtesy will not throw you off the edge of platforms lol.
An interesting consequence is you could give the linear aoe sticky targeting, where just like art of war if you tap it just happens to your target, but if you held the skill down it will show the aoe marker (line aoe in case of Samurai's dash) where you could perfect the distance BUT ALSO you could use the attack in a different direction than the monster and with no monster as a target in general. By sticky I mean if you make slight mouse or joystick movements it wouldn't really budge the marker (like assisted aim in FPS), but if you gave it a stronger movement it would dislocate from the enemy (or in the case of no enemy target it would just not have a sticky lock, but would default to aiming directly in front of you).
Dancer dash for example would still behave the same as a tap skill but if you held the skill down you could aim the dash, and there might be some skill upgrade later that's like "allies in a radius of X near you gain 5% hp and x.. or whatever lol"). Reaper portal could be aimed as well (if skill is held, if you tap it'd act exactly as it already does).
Ninja with the improved QoL on a tap would just teleport in a given direction without confirmation (akin to a dancer dash), but holding it down would work as it currently does*. *Also would like to see Ninja teleport ignore terrain and work as an actual teleport once you unlock flying in the zone. I know it's relatively pointless but I feel it would feel pretty spiffy, so long as coding that isn't too hard I think it's worth it (just like I think Dragoons should be able to super jump by like holding spacebar and releasing, in areas they've already unlocked flying).
Esc canceling any held action ofc.
Going back to conals, might change many conals to circles but maintain the conal is an optimal place to take action. Or alternatively if you're far away it will be a conal but when you get near it will be a circle (so warrior might have this epic long range overpower, but it changes when near). Which would give Warrior neat flavor but not really be a huge balance concern.
The whole hold concept moving into almost anything and everything, like blue mage bad breath could be aimed or if you tap it'll just do what it already does. Skills that are normally target could be -auto cast-, skills that are normally auto cast could be aimed. If you wanted to aim your thunder aoe spell as a black mage you could hold the skill down, but otherwise it would sticky lock to your target (and functionally has no change over what you already know it as).
Few other examples of using distance or sweet spots, like blue mage gloom (teleport skill) is instant cast under X distance and is a short cast over y (I still think it should do something else too though like removes one debuff, and grants you a minor shield if it removes a debuff). Another example of conditional distance (and other conditions), might be for example with Summoner if you're X distance away the egi are summoned AT the target but if you're within like a couple yalms it summons at you. All the "first enemy hit deals more damage" concepts could be visually represented by a small concentric circle on the aoe marker. Ram's voice now having the ability to 'hold' the spell so you can see the donut (tapping doing exactly as it had done before). New spells might have alternate aoe markers, like if a skill first did a donut of damage and then a inner space- or if it was a conal that did damage in a wave (as MANY bosses do, all that could be represented via the multi-highlight system introduced by sweet spots).