The paragraph about heightening spells for the Magus is ambiguous about whether they can automatically fill higher level slots with lower level spells, or if they have to learn the higher level version of a spell before they can cast it at a heightened level (as opposed to just filling a higher level slot with a lower level spell to cast it at the original level)
Can we get clarification on whether a Magus can automatically heighten spells in their book, or if they need to learn the higher level version first?
Never mind, was thinking of the need for spontaneous casters to learn at a higher level. Having reread normal Heightening, a prepared caster can just prepare it at a higher level to Heighten it