Right now the only kind of Event Handler for seeing if a projectile passes near a unit is Suppressed, however this only activates if the shooter is an enemy, and the wiki note about making use of setFriend has a rather limited use case.

A useful addition would either be:

• A Standard Event Handler, similar to Suppressed, that activates when a projectile from any unit passes near, not just those that are from an enemy.
• A Projectile Event Handler, that activates when the projectile it's attached to passes near any unit, regardless of the side of that unit