It’s been a while since refunds were stated as possibly coming. I was curious if any headway has been made on that?
We have a module that adds refund support for Mollie: https://docs.modmore.com/en/Commerce/v1/Modules/MollieRefund.html
The plan to add support for other gateways into the core has admittedly fallen of the roadmap, and surprisingly doesn’t come up often as a request. That said, we have made at least a portion of the changes to the core necessary to add it, like payment states that include refunded states when negative transactions appear.
But yeah, other than for Mollie with that extension, currently refund need to be processed manually through the payment provider, and then added as a manual negative transaction in Commerce.