FFF
I would like to think that in 13 hours a qualified pilot would be able to master, the rudiments. I know that students have different learning curves, but we are not talking about students here. starbuck is a qualified PPL and to be honest the tailwheel element is not a big deal. There is to much macho BS talked about it. We are not talking about mastering the beast ( I still can not after a few thousand hours tailwheel).
It does depend on the instructor and student continuation; but unless the student is of poor quality 13 hours would be a good target for a First solo. This is teaching wheelers and three pointers. That is from 0 hours!!!!
There is a lot of Bollox, written about tailwheel flying. The most important thing for any new student is to have confidence in what they are about to do. And mostly be prepared for serious fun.
Regards to all
Wide