I don't know if we're talking about the same part or whether I'm missing something?
It's the black section behind the silver VW badge. I've even applied some of the silver look wrap that I was given on there as a dry run. It held no problem, I just didn't cut it to shape/size because the colour match was sh1t.
It looks and feels fairly smooth. Put it like this, it's not the bobbled finish that the standard GTI skirts and bumper have which I wouldn't have queried because that would be a bad surface to try and wrap, whereas I don't believe this is.
It's not a perfect surface admittedly but it would hold, as tested.
The main curve ball is the small dotted holes where the badge attaches, hence why painting as you both suggested is the best option overall