Some good news. I've got NSS wifi offload working on latest branch of main here: qualcommax-6.1-nss-wifi. Used @dimfish's qualcommax-6.1-nss branch as a starting point.
Everything seems to be working, but it doesn't seem stable. Boots with a ton of:
ath11k c000000.wifi: peer not found for nss peer delete
But it eventually seems to subside. So far it's been up and running for a few hours. Still needs a lot of work.