>Minute it clears land shoot it down
Is probably how it would end, but think if you could get it intact you will find out 100% everything that needs to be known. Water is safe if you don't hit target, anti freeze could give the right freezing properties that a scientist/mathematician could figure out.
Another suggestion is send our own "balloon type" that we control, to TOW it. Maybe get close enough then launch a harpoon like tether and reel it in, close enough that it is more easily controlled. Intact would bring hordes of information. Maybe call Elon he might have suggestions.