I have reservations about running either the agent or portainer itself on something external to my lan.
I don’t feel like it’s safe enough personally either, so I just have portainer edge-agent nodes connected to the primary on my intranet through through vpn tunnels. I really, really would prefer not to ever open ports on my local firewall, but being able to monitor and control remote docker hosts is also pretty convenient, so my solution has been decent for me.