In my opinion Zelle - which is the banking industry's answer to the cash app and venmo/paypal - is a very good solution but still poorly marketed. Many folks don't know zelle is "built in" to their existing bank account (meaning there is no new app to get or account to create), so the individual with a checkbook very likely can use zelle from that same account but simply isn't aware. Talk them through it - both you and the buyer will be happier than with 'check in the mail' timeframes/risks.

-Rob
-visit https://www.kahr.us to get my daughterboard that helps fix WPC pinball resets or my replacement type 1 sound board for Williams system 3-6