Disable Cancel Spell via Double Cast

Is there a way to disable the cancellation of spells when casting the same spell again?

When things gets hectic in the game for a WHM that's trying to cast multiple spells, the last thing I want to worry about is wondering if the action I've pressed is actually casting the spell or not after the end of another spell. If it is, and I've hit it again, it'll cancel the spell, even though the spell casting timer didn't show up. If I try to wait it out and it didn't register my action, then I would be standing there wasting time waiting for a casting timer to show up.