So, momentum spends in spells. If a player wants to cast a spell, using cast for consequences. And adds up all of the spends he wants. For argument sake sends it above D5.
A) Can you only ever have a max of D5 spell, and must stop adding spends when reached?
B) You can add additonal momentum spends over and above 5, but the spell is ranked as a D5 and will never get higher?
C) Your spell is ranked as per momentum spent, so the roll is based on the actual total and not capped?