The requirement of managing an LDAP or AD directory service just to get some auth for NFS is a dealbreaker for like 99% of people. It's such a dumb protocol for the average user and was designed with only huge corporate clients in mind.

Just give people a simple password auth or let them exchange private/public keys between the devices that need to connect!

Is bluesky also activity pub?

Why are you trying to maintain an instance list? Just ask the user to input their instance URL. It will simplify the code and make it extensible to self-hosted instances and you don't have to try to list every lemmy instance in existance.

I cannot fathom what a respectable website would need with a port scan. They should normally just be listening to/broadcasting on 80/443. Is it looking to see if the normal html ports are remapped? That's the only reason I could imagine.