I have an idea about notifications on the website, maybe dev team can add a sound signal on the website for notifications like in some web messenger?

If test.io tab in a browser is open, when tester gets new notification (invitations, test archived, bug forward to customer or rejected etc.) with some notification sound. And tester can set what notifications he wants to get with sound in notification settings. This will allow testers not to miss any notification. Especially new invitations.