It should definitely be possible to setup NGINX & HTTPS to have your i2p router accessable at that domain, but id recommend just using the ssh tunnel with key-based authentication only, it adds an extra layer of authentication and encryption that cant be bruteforced or guessed.
But I strongly advise against having your I2P router bind to a public ip address with just plaintext HTTP
I've never used this app, but it looks like its using i2pd, I would look for the
i2pd.conf
, and change the bandwidth flag from L (32kb/s) to like O (256kb/s) or P (2048kb/s), but performance may still not be very good if your router is firewalled.But you might just be getting bad peers, the speed of a tunnel will be limited by its weakest peer, I would try increasing tunnel quantity on both sides, and allowing inbound traffic on both routers if they arent un-firewalled already, if possible.