I'm not sure if it's possible to program.
But then again, they did it in Monstrosity.
When you level up you automatically gain spells or JA's (sure they show up at the bottom of your list, but that's besides the point).
As long as certain JA's and spells are in a list for a Trust to use, their combat AI should be able to implement them.
However, I think it's the increase in stats and mainly auto-fill of HP and MP is the reason why it can't work.