A big part of math is building up your toolkit: when I see x, I should do y. Feynman famously made this a big part of how he approached quantum mechanics, saying that it was his toolkit that allowed him to solve problems others saw as impossible.
While the initial understanding can't be done with spaced repetition, remembering what's in your math toolkit and how to use it can very much be aided by spaced repetition. I've personally used this to great effect teaching people math through my spaced repetition app.