That looks very interesting, good find there and I'm sure someone with the right skills will be able to make use of this. I have now been escalated to an Nvidia programmer and I'm awaiting them getting in touch so I will report back with whatever I find. If you have any suggestions of what to ask for then let me know now.
In other news, I think I have been too hasty in writing off the Dell 9560 - perhaps when I received the laptop I had several days of migraines that I was going to get anyway. Since then things have settled down - I reverted back to the oldest possible drivers for the GTX 1050 (381.65) on Windows 10 version 1607 using ditherig.exe to sort out the Intel 630 dithering, and I'm using the laptop comfortably for my second day now (used for 12 hours yesterday). I'm unsure of whether the roll back of the drivers has helped but I'm not going to mess with it for just now. So, good news!
I will still push for Nvidia to confirm whether they have enabled dithering and for options for disabling it within Windows.