I tried Easy Switch to import my Google Workspace accounts. It imported the main account fine, but I wanted to import another Workspace account into my main ProtonMail account in order to consolidate them, but Easy Switch kept asking to create a new ProtonMail user, which I do not want to do. That made the switch so much harder than it needed to be, since there is no simple way to import a local mbox file without having to first download, install, and configure TWO OTHER APPLICATIONS (Bridge and Thunderbird), and it STILL doesn't entirely work. I'm posting a separate feature request for the mbox import.