Good points, but I'm not sure what you mean by paperwork. I don't have engineering certification if that's what you mean, but I doubt many of "us" (modification junkies) do. If it's easy enough to get engineering approval, I'd be interested, but that's another thread I suppose.
From my limited understanding, the HTV1900 S/C is ADR approved, but that doesn't mean much in regards to legality issues (emissions, engineering, etc).