Do you not find The chain rubs on the chain stay/protector when its pushed up?
Ive used a rubber wheel tensioner before with zip ties. It stopped it skipping but the tension wasn't very good and it rubbed on the chain stay. The zip ties always stretched and I want to get away from using them. Going in and out of the car when the rear wheel needs to come out to fit us all in is a hassle I don't want anymore.