@Riot Can we please have it where smiting an enemy champion grants assists?

You must deal damage, apply CC, apply a debuff, or apply a buff in order to get an assist. Chilling Smite deals damage and will grant an assist, Challenging Smite doesn't deal damage unless you AA the target, and while the vision is a debuff, I don't think assists are given for vision debuffs.

This doesn't already apply?