Is there any way to cast (or prepare) spells while stunned (I don't mean stun relief, just ordinary spells)? Is it always disallowed, or do you get to make a SCSM? If so, with what mods? I assume that whatever goes for casting spells normally, also goes for casting spells from items.
The rules say something like "The only other allowable actions are movement and maneuvering (modified by at least -50)." I guess SCSM can be seen as a maneuver, but still...