I am very much in favor of the idea to be able to exclude spells from being cast. Although this wouldn't directly solve the issue with not casting the right resist, it could be made into a potential workaround. Besides, having an ability to disable the spells would be awsome on its own (something like a checklist next to the spell list when giving orders, with all spells checked initially and then being able to uncheck the ones that you don;t want your mages to cast). Hopefully some day this will be possible.
