Sadly only threecards that say "noncreature spell" around my power level.
or ?Also, if you stretch your definition of prowess payoff
In my mind for spells matters to really pop, cantrips are essential to allow you to chain spells together. With your current build you have two in White. I'd like to suggest
This is a role player for many archetypes, highly recommend. There aren't a ton of these effects in White, so I think it's worth playing them all. Maybe Scout's Warning is worth a slot too.
There are also cards that allow you to recast your spells over and over, keeping the prowess triggers flowing. You have a few of these, I also like
Return a land for a landfall trigger. Bounce an adventure creature. Return a "Living Weapon" artifact. And so on.