FWIW, I was able to change the user-agent string in both Microsoft Edge (tried on Linux and Windows) and Opera (tried on Linux) to enable Cam Pan v4 streaming in those browsers:
Firefox is a no-go, but it’s not Chromium based. I tried using User Agent Switcher and Manager to spoof the user-agent string in Firefox, but the browser itself is just too different and won’t work with this Cam, at least as far as I can tell.