While you are getting great results from your hanging strop, I think it is unfair to say that a paddle strop with similar leather would not provide the same results. Paddle strop is not my preference by the way, but you should be able to get exactly the same results with a paddle strop.

I too used a disposable straight (Feather AC) when I was learning to gauge the sharpness of my other straights. I still use my Feather AC when I am in a rush and want to save a few minutes on stropping.

Congratulations on your progress!