Hey! So for the Het enchancer to be active on AG you'll need to start a new streak and have the enhancer with you (this'll then mark that new streak as enhanced)

(otherwise you'd get some nasty loot rerolling if you did or didn't bring the enhancer due to it being seeded)

As for the drop chance, your unique chance is directly increased by 10%

Numbers from our drop rate post:

Streak: 1, Enrage: 999 - 1/91 chance of a unique drop

Streak: 25, Enrage: 1500 - 1/60 chance of a unique drop

With Het enhancer:

Streak: 1, Enrage: 999 - Roughly 1/82 chance of a unique drop

Streak: 25, Enrage: 1500 - Roughly 1/54 chance of a unique drop