Magical safe-target system? Options

[Dancer]

You can only cast direct spells on targets you can see. *ball spells hit everyone in an area, including targets you might not want to hit. Unless, of coure, you can't see them.

Imagine a mage with cybereyes. A moment before he releases the Manaball into a crowded room big black censor bars pop up over his teammates, blocking them from his view. A moment later, they disappear again. He had previously designated all his teammates in the same manner as you would for a smartgun safe-target system, and used his free action for the round to trigger the software.

A mage without cybereyes could presumably use AR-style contacts, so his sees his targets with normal vision but digital graphics block his view of his teammates.

Is there any reason this wouldn't work? Or is it in use normally and I've missed it?