This is for EP8, of course.
I would like casting spells not to shift your alignment (good, neutral, evil) so that you can cast spells of any alignment without worrying about changing your own. Of course, the spell book would still be usable to change alignment so that it would be possible to do so.
If this is impossible, making a version of your "cast any spell" mod that makes all spells evil (instead of neutral) would also work.