RE: Klass Kote Primer over Polycrylic?
If there is a concern about the paint cracking on fabric, you can add a plasticizer to the paint. It is a common thing for the popular "rubber" bumpers on today's cars. It's been MANY years but (I think ) castor was added to dope as a plasticizer to help prevent cracks or maybe even help control shrinkage.
Ken