Esposible
Since he can copy magic and use use. Why don't you just let him write in air as mana projectiles. Remember I'm not taking about spells, I'm talking about runes and word magic. With that, he can use his powers with greater potential. And since he can see and copy magic spells, with his knowledge, he should be able to make new spells. And since you mentioned that, I will say that even the simple mana manipulation have greater potential that all the spell spamming. You can create projectiles, walls, armours, weapons, protection sphere, atom manipulation, matter manipulation, super minor reality manipulation. etc. There is so much potential in Mana Manipulation.