I presume with Stripe you can only send from your Stripe balance, which certainly can be funded with credit cards (yours or others), but you'll pay the 2.9% + transaction fee on the "inbound" (CC) side, which (I think?) would cost more than the miles. In that scenario you could skip the debit card part entirely and just charge your own credit card and have the money go to your bank account.

The miles hounds have throught through these scenarios pretty thoroughly :)

One major bank set up an online payment service in the UK about ten years ago which allowed you to load money, fee-free, from a credit card, and then pay other people. Of course, said money, once loaded, could also be withdrawn back to your bank account, but why would anyone do that?

WHILE airmiles < MAXINT do { load, withdraw, pay card bill }

Round and round the money goes. :)

Obviously the fee-free aspect was unusual, perhaps an oversight but more likely an attempt to get some critical mass in the online payments market which, at the time, was primarily only PayPal and a UK outfit called "NoChex" (which of course DID charge a fee.)

Eventually a loading fee did arrive, and a little later on, the service closed up shop entirely.

At 3 cents per mile, everyone is happy but you. You can buy frequent flyer miles from your airline for ~2.5 cents a mile.

As a fellow "travel hacker" that was the first thought that crossed my mind.