Hi Justin,
I just tried installing Mail Boss. Using Chrome I got the pop-up window describing Googles new financial extortion policy but when I clicked on the Enable Mail Boss button at the bottom of the page nothing happened. I switched to Edge where clicking the button resulted in a message to disable the pop-up blocker. After doing that clicking the button gives me the following screen:

As you can see this is different wording to the screen you describe in your installation instructions and more importantly it doesn't provide any options to proceed with the installation anyway.
(I also tried disabling the pop-up blocker in Chrome but that still didn't even get me to the above screen).
Are you aware of this issue and do you know of any workaround?
Andy