@katernoir This doc has some more information about the /dial_peers endpoint. You need to enable it by setting [rpc]unsafe = true in your config.toml.
Also for enabling autoscaling you will need to be taking regular snapshots of full node state in order to quickly spin up nodes. I’ve got a high-level overview on how to do this using GCE in a notes github repo.
@mattharrop Looks like this issue will be fixed by the external_addr option added to the config. That will be available for the upcoming testnet.