I was surprised to learn this was a thing, impressive, however;
‘the VPN app sends a request to the VPN server to open a random port’
‘the active port number will change when you disconnect and reconnect the VPN.’
This will not work OOTB with Plex for example, you would need to change the port in the app every time. It becomes difficult to serve anything statically, like a XMPP server or anything that doesn’t let you configure the port.
You also would need to be at home to check which port you’ve been assigned eg if the connection drops and you get assigned a new port, defeating the whole ‘remote access’ thing.