Neat trick.
I think for the effort, I would have hammered in a torx bit, then if that failed I would have just skipped to welding a nut on. If you’re worried about spatter, toss a blanket over what you care about, or use a TIG. Remember, you only need to use the welded nut once.

I know you’re a super sharp guy, but I think I would not reuse a damaged bolt