Getting the wifi offload + memory usage were the last few pieces of the "full offload" puzzle. And as a whole it's been a pretty stable and performant platform. Especially in regards to wifi performance when compared to Mediatek, and even Broadcom (I had but returned the RT-AX86U on Merlin FW).
QCA's codebase is all over the place, the GIT commits may as well be "did some stuff", "update", "blah". The QSDK release schemes have no rhyme or reason to discern between features, bugfixes, backports, etc, and the documentation is non-existent.
Majority of my NSS patches have been a complete shot in the dark... But by some miracle hasn't blown up in my face and chugging a long 
.