I think that all spell should be castable on the SOE: the Lighting is weaker, and other spells works only in your own territory (so you can't use them already) or on your own creatures (so you can't use them already). So, yes, I think that should be possible, and should be in the level's Author interest to decide how it will works (for example, he cannot give the SOE or maybe can design a specific use for this and similar).