Hello @gertjan!
Thank you very much for clearing out my doubts.
This was troubling me for quite a while that why there's a restriction in changing management interface.
Even after adding management 127.0.0.1 7505 directive using Custom Options, the OpenVPN instance on pfSense always used a UNIX socket. (It opens a UNIX socket with IP address as name)
Because ..... that is the way how the Dashboard Server VPN widget 'scans' the OpenVPN server so it can update the dashboard info about a current connections.
This is the crucial information I was missing. I will check the documentation again to confirm if it is already mentioned there. If not, I will open an issue/pull request to add this.
But now, I want to take a dive into the implementation of the "scan client" feature and would like to investigate why usage of TCP ports has been ruled out completely.
It will be really helpful if you can provide links to related code or documentation which can give me a starting point.
Again, thanks a lot. :)