Thai embassies in various countries are renowned for printing fairytales.
NZ is not alone.
You state.....
"...then 2 NK crossings. Last one in early NOV. Tomorrow will be my 4th entry (third NK crossing), if successful"
Please report back your experience to the forum.
A safer option in future is to use agent minivan company for border bounce.
You must have reason to be using NK.
I'm not aware of agent doing that run from Udon Thani to Nong Khai
Won't be long till there is if reports similar to what's in this thread.