Okay, so after 30 million years of searching and reading and swearing and cursing, I've finally found the "BrowserCommand" configuration directive. So I set my C:\Program Files (x86)\pgAdmin 4\v4\web\config_local.py to:
But when I then click the pgAdmin 4 start icon ("C:\Program Files (x86)\pgAdmin 4\v4\runtime\pgAdmin4.exe"), it *still* opens Firefox (default browser) with the DEFAULT profile. In other words, it ignores my BrowserCommand, which tells it to open the URL in the "pgAdmin" profile, which I've spent significant efforts setting up just for pgAdmin 4, so that I can finally use the program without being constantly harassed for passwords and losing all my work whenever Firefox needs to be restarted.
And no, there is nothing wrong with the command itself; I use it with other profiles. But pgAdmin is clearly ignoring it. What's wrong?