Move the Elavon Payment Processor extension out of core
I have just installed CiviCRM 5.66 for a client and I see it ships with an Elavon Payment Processor extension.
I have never heard of Elavon and I believe this extension is very usefull but not in the use cases I have seen so far. (They use CiviSepa for direct debits and Mollie for online payments both are not shipped with core).
I also believe that an extension which lives outside of core is also easier to install on CiviCRM installations which does not have this extension shipped by default (when needed).