Ben did do backup lessons for Big Sciota, Keep on the Sunny Side and St. Anne’s Reel at the end of the main lesson.
I’m two years in and my backup ability is pretty non-existant. However, with what I know now, I can understand Ben’s approach in these lessons. His backup lessons are pretty loose and are mostly about teaching us how to attack the idea of backup using the tools we have.
He might be able to do a backup lesson like you want (when I was first starting, I was hoping for this type of lesson too) but you may end up only being able to play THAT backup to THAT song rather than being able to make up your own backup, which is the direction his other backup lessons take. Check them out.
You can write Ben using the Contact link. He reads all his mail and has always replied to me when I sent a message.