I use 4 virtual desktops to organize my work (the standard workspaces that you can use with GNome). Email/Calendar stay in desktop 1. When a meeting is near to start, the notification notice pops up in the middle of my work and captures focus, only if I am in the same virtual desktop. If I am in desktop 2, this does not work.
I managed to get pop up notifications in all the virtual desktops setting the window property "Always on visible workspace", but this mean having the browser always in my current workspace, which I really don't want.
I've tested this with Chrome and Firefox.
Is there anything better? Maybe some tool I can install?