Good Evening, @40Carrots. 

Thanks for reaching back out to the Community. At this time, there isn't a way to show the preferred payment method for a customer on an Accounts Receivable or Collections report. However, I'll send feedback to our Product Developers so they can consider this in one of the upcoming releases for QuickBooks Online. 

Here's an article that can provide some additional information about customizing reports in QuickBooks Online. 

If you have any other questions or concerns, don't hesitate to ask. Have a great day!