I got this I2Pd installed and it works fine except that I need to change proxy settings of my computer every time I want to get on ".i2p" site. As it it has always this i2p suffix, is there a way to get it going through the name resolution somehow?
I don't quite understand what you are asking.
Do you want an easy way to switch between browsing the clearnet and I2P? Maybe this is what you are looking for?
Or do you want the browser to use the router as the proxy?
SNI using SSLH, plus i2p mapping in dnsmasq should do it.
I don't know how i2p proxy works, but here's my scheme for HTTP(S) "router".
Multiple Wireguard/OpenVPN tunnels to different destinations.
Docker running on OpenWrt, each container has its own IP address.
Multiple containers running TinyProxy, all using same minimal configuration.
Policy-based routing (PBR) routes traffic from each container via its own Wireguard tunnel.
In Chrome I use ProxySwitchyOmega to route sites based on URL (regex available).
I think this scheme cold work with an I2P proxy as well.