thanks for the photo! The rubber soles of my pairs look quite thin, like your blue ones (the SA sent them like that to me from the store), which is why I want to add an extra layer to protect the original soles. I've been wearing them about 5-6 times already so I think it's time to protect them to last longer!Here is the pix of projective soles on a brand new sole and on a used sole.
Black: this pair were in really bad condition that I was considered giving away. The cobbler had to remove the original sole, put on new sole and glue the esparto rope.
Blue: the cobbler kept the original sole, just added a protective sole on top of it View attachment 3729978