I think they could have simplified them a lot by just making them into MDFCs. This also lets them adjust the mana cost depending on which variant the player chooses.

Otherwise, I'm always in favor of adding depth to existing mechanics. Read ahead was a great mechanic for giving the player choice, the summons were a cool way to create powerful, temporary creatures, sagas transforming on their last chapter gave them staying power, etc.

I do have to wonder if they'll ever revisit battles though.