with modern sophisticated made damascus steel you can shoot probably anything you want but with this late 19. century handmade damascus from Liege where is the end? some do it and shoot light nitro for black loads but you are allways on a thin line.
someone must do the work and pressure test all this loads you can made, blackpowder and nitro loads to have a scientific basis about this problems. but it will cost realy a lot of money and this only for a handful of vintage double gun lover.

I cant see someone will do this investment!