Not only port 22 for ssh should be changed or at least permit the user to change it. There are other services that should be changed also, like http or https.
What happens when you run an web server on the LAN side and need to do a port redirection? Right now, the only solution is to change zeroshell web server using a cron job to execute after booting, and that is not a clear nor elegant way of doing it. It involves some knowledge of bash, linux and apache to perform that task.
It should’n be too dificult to implement that on the web interface and have the changes be permanent on the Database.