Coin control is fundamental for #bitcoin transactions privacy, but it’s annoying to have to handle the change output and keep track/label on every spend.

What if merchants accepting bitcoin could let me create a simple payment channel address that can be funded spending an arbitrary amount of coin(s) without generating a remainder, hence no change output in the transaction?

User wallet would send funds and right away sign the initial state deducted of the first spend in favor of merchant

ie.

Funding amount 0.1525 BTC

First payment 0.01 BTC

It a basically the Bitrefill account balance, but with somewhat a guarantee you can get back your “gift card” if service is not delivered to you anymore.