@Sky-Knight,
I honestly don't know. I constantly have 3 email addresses active, and sometimes a 4th, but even then I keep each one open in its own webmail session in a separate browser window, whether that be by using different browsers, or three or 4 private/incognito windows, one per active address.
I've always hated "unified inboxes" and even when using an email client kept all of the accounts as separate entities (though not going to separate profiles).
I like having each respective e-mail world unto itself, and that's a simple matter even using a single web browser and a couple of dedicated private/incognito windows. But I typically have an instance of Firefox, Chrome, Brave, and Edge going at any moment in time, so just having the 3/4 open, one in each of those browsers, works too, and is most often what I do.
It's all about what works for any given individual, and some would never do as I do, but the problem is that many have no idea that they could do so, if they so chose, so presenting this as an option never hurts. If it's rejected, then so be it.