That makes sense in the context of a halogen reflector to hid/led projector retrofit but I don't understand why that would be an issue with a housing already designed for hid use.
The issue isn't limited to halogen replaced by HID or LED, it also applies to replacing one HID/LED projector with another, different HID/LED projector. It would be OK if you were swapping in another set of exactly the same projectors -- real ones, not counterfeit knockoffs -- and if you don't have to take apart the headlamp to do so (no "baking" the lens off, etc).
Perhaps I am wrong but when I think of issues regarding outer lens refraction what comes to mind is upwards light for illumination of road signs.
The issue is more with glare and seeing as well as the physical issues (center of gravity, etc) described at the link.
The one I am looking at is almost identical in output to my current projector with the small exception of having slightly wider output.
So not an exact replacement (and again, good odds not a legitimate projector). How are you determining that it's "almost identical in output"? It probably is not, and even if it were, different projectors can arrive at similar beams via very different optics, which means all bets are off with regard to compliance once installed.
The website you linked was in German and I am not located in Europe.
Neither am I, and that hasn't stopped me from sending them lamps and parts for refurbishment and receiving them back in like-new (sometimes better!) condition. This is the internet...we have tools like Google Translate to help us, and even without that, they speak English just fine.
