Entanglement, primarily, of both feet, and—if well aimed—could serve as a temporary muzzle, if only long enough to help facilitate the boarding. It would be easy enough to fire, and something that easily be charged to expand with magic after it has reached the target.
In terms of security for the boarding party, there isn't much of a way to make a safety or fall net that is reliable, though its possible objects could be enchanted to help slow the momentum? Or the crafting of parachutes, but that is far more clothcraft than metallurgy. My only thought would be towards something that could be secured into the scales, like climber's equipment, to aid in grip, but there we reach the speculative balance of estimating 'how much damage into the dragon this causes' to 'is this secure enough that it won't fall loose' without any true knowledge of how tolerant the scales are.
no subject
In terms of security for the boarding party, there isn't much of a way to make a safety or fall net that is reliable, though its possible objects could be enchanted to help slow the momentum? Or the crafting of parachutes, but that is far more clothcraft than metallurgy. My only thought would be towards something that could be secured into the scales, like climber's equipment, to aid in grip, but there we reach the speculative balance of estimating 'how much damage into the dragon this causes' to 'is this secure enough that it won't fall loose' without any true knowledge of how tolerant the scales are.