Ability to limit coupon to newsletter customers

I'm trying to setup a coupon in PC 3.11 and I see that you can limit the coupon by particular customers.   However, there's no way to filter those customers by whether or not they've opted in to receive your newsletter.    I like to send coupons out to my mailing list and I'd like it to be somewhat exclusive.   In other words, if someone on the list decides to forward the coupon to other people not on the list it shouldn't allow them to use the coupon unless they first register and opt-in to the mailing list themselves.   It encourages increased sign up to take advantage of the coupons and it also discourages abuse of your coupon codes if you're trying to reward only those who have signed up to your mailing list.

The functionality would need to be dynamic, it couldn't just be an extra filter to the customer search that when you're creating the coupon because then it would only include those customers that were opted-in at the time the coupon was created.  The coupons in ProductCart are already capable of checking a customer's record and seeing if they're eligible for the coupon, so in this case it would just also be checking to see if they're opted-in when they're placing the order, if not the coupon won't take.   This way if someone new signs up for the mailing list after you've created the coupon it will still allow them to use it.

My two cents...