Looks like it’s not all that hard, jsut have to give home assistant some additional permissions to networking at a lower level of the stack

Basically, yes

That’s not why port forwarding is important. Port forwarding is needed so that fresh peers can communicate with you and join the swarm. That act has the side-effect of speeding up transfers by allowing more people into the swarm spreading the transfer across more potential seeds/peers

It’s one of those things that gets faster the longer I2P software is running. As I understand it, it takes time to building link betoween yourself and other members of the network in a safe and secure way, but once they’re built up that extends your reach and speed