naveed-coupons

[quasi nymph]

I'm not sure sure what happens when you apply a coupon with a higher amount_off than the purchase it's applied to (maybe it does get added to the customer balance, not sure), would have to test that

[storm saffron]

ill try it out and paste here

[quasi nymph]

yeah I tried it and that's not the case

so ok.
What you could do I suppose is manually update the customer's balance for the difference between the applied discount and the overall coupon(ie. compute the difference and call https://stripe.com/docs/api/customer_balance_transactions/create) . That is then offset against any future invoice payments they make.

and yeah you'd have to build this yourself, not aware of any in-built automatic options.