I’m confused. If you login to the Starlink app then you should see all of your subscriptions, and no matter where you connect from. Also from there you can control dishes remotely.
According to this other post on the forum, the big reason to use the “Management IP Address” feature is to get direct access to debug data on a modem.
Personally, I leave it disabled unless I need it because both my cable modem and my Starlink dish use 192.168.100.1 for this purpose.