Hi all,
Thanks for your votes and comments on this idea. I'm pleased to advise this feature has been implemented in version 8.3!

Check out the release notes here: https://docs.whmcs.com/Version_8.3_Release_Notes#Affiliate_Commission_Reversals
The feature documentation is here: https://docs.whmcs.com/Affiliates#Delays_and_Reversals

We hope you find this new feature beneficial!