It would be great if the discount code(s) on the payment record were linked to their edit screens, as the record is a hub for everything else related to the payment.

If everyone agrees, this would be a great addition once EDD_Discount is ready. https://github.com/easydigitaldownloads/easy-digital-downloads/issues/5217
Yep, it's something small but a nice addition at the same time. We'll write the code up once #5217 is merged.
In #5217, I've added an edit_url() function to make this even easier.
Commit ref: 30c42bc7e817e7b0cfd80b3ad7fc9b78ffc0a1c8
Reopening for some visual updates.
PR tested and I'm happy with it 馃憤
Beautiful. Thumbs up from me as well. :+1:

Merged into release/2.7
Very nice!
@SDavisMedia Improved discount list ftw!

Most helpful comment
Yep, it's something small but a nice addition at the same time. We'll write the code up once #5217 is merged.