As far away as possible. *You don't want to blow conditioned air into the
room to have it sucked out immediately. *Direct the supply away from the
inlet of the fan.

Just a thought, Broan makes fans with heaters. Would not the same
thing happen with their unit? I was considering one with heat. My
register is for both heat and cool. So thats why I am unsure as to
what is usually done.