So we're still at the persuading the graphics team to even work on this stage...oh dear!
i assume that the new driver, if it ever arrives, will also fix the same issue I'm having with a Gigabyte Brix Pro, which uses Intel Graphics 5200 and behaves identical to the NUC in this respect.
Stunning oversight to not have VNC etc working headless for these boards, remarkable that several months later we're getting posts like this talking about hoping to get some other people to prioritise it - no offence to you Lois, thanks at least for posting an update 