With Da Vinci Tools enabled in Chrome, switching between Google accounts no longer works. Either using the GUI or manually changing the authuser number in the URL (https://tagmanager.google.com/?authuser=0). It fails in both directions with two accounts logged in leaving you stuck in the one you had logged in. Confirmed it's DVT by disabling extension and refreshing, where it works again.
In case it's relevant, one account is a paid GA360 account while the other is a free one.
Customer support service by UserEcho