I agree ... but honestly dropdown menu seem like horrible idea (sorry mate) ...
Its kinda anoying to choose hex debuff every time ... and its only every enemy ... if i had to do it every cast, it would be even worse. :-/
I dont see any problem for dropdown menu if anyone wish it ...
Myself, i would like much more if you will choose spell level by toggle spell slots ... after all, we see them.
Not sure if i make myself clear, since my english is horrible.

So example:
Mage goes on turn, i see in UI how many spell slots i have awiavible ... so i click on spell slots level 2 ... and now all my spells are level 2 until i click on different level, or until all of them are used, then i get system message that i dont have enough spell slots of required level.
//edit: Ofc. if i clic on spell slot level 1 ... and i will have on bar some spells that are only level 2 (and stronger) they will simply become grey ... aka. unavailable.
