Remove the need to flip between accounts
I suggest removing the need to flip between accounts to see news feed, chat, teams and channels for each account. Once you're logged to all your accounts you should be able to see all of these from the same area regardless what account they're part of. Flipping between accounts to see these things is inefficient and also is problematic with notifications.
Anthony G commented
David Reavill commented
I work in a consulting role with both a home company Team account and a customer Team accounts. Switching accounts is very difficult in the app. It is easy to switch accounts in the web app, but comes with limited functionality, e.g. no desktop sharing. Best solution would be to support account switching natively in the app.