I'm quite amazed why so many do not pay attention to this thread as the NSS cores are insanely critical for the IPQ806x routers. NSS core do all the heavy networking including the same thing IRQBalance works + you have 2 cores that do completely nothing as all the load is on NSS. I'm currently on the ZyXEL NBG6817 / Armor Z2 (AC2600) which does have the same specs as the R7800 But i'm too scared to use your firmware as i don't have the equipment to debrick if required.
I'm currently original firmware because of streamboost + nss cores, since openwrt firmware can't handle 400/40 mbit connection over wan not even with the "flow offloading" and the "hardware offloading".
What do you suggest + have any ideas what i can do to help you out with the nss issues. Is it even possible for me to use your build?