Update, the tech didn't write back to me again, but I didn't really expect him to either. He's an outsource.
The good news is, I don't mind that much. I still hate Windows 10, its ugly interface, and all its inconsistencies, BUT, I am able to use LTSB 2016 using the usb box that has a displayport on it on the desk monitor. After having changed the color temperature to 4200K to match the ceiling lights close enough, and turned off as much of the stupid font anti-aliasing as I could. So I guess I got used to it which is good news because it means there is no immediate emergency.
My home pc has both a hdmi and displayport out, and I use the displayport one, because like the work laptop, I find the displayport output to be subtly more stable in some manner.
But holy, W10 is so janky. I'm forever fighting with the thing to set the % scaling, etc. and rebooting or whatever so that apps stop rendering with blurry text. In a bunch (esp. internet explorer) I can end up with cleartype anti-aliasing, greyscale anti-aliasing and no anti-aliasing all on the same page. Yes. All 3, totally serious. Incroyable.