@anyx would probably be a better person to ask about this. I am pretty familiar with the witness node portions of node configurations, but not as much in terms of the API calls. He is an expert on that.
One suggestion would be you could start with a seed and open the ports, and see if it rejects your operation. If it does, dig into which plugins need to be turned on to support it.
There is also some documentation on the APIs here:
https://developers.steem.io/apidefinitions