I frequently want to work with Fibery open in full screen on 2 or 3 screens. Yes, it’s that useful… 
Currently I’m restricted to working on 1 screen and it’s quite a workflow killer. Yes, I can open a browser on multiple screens but it’s a subpar experience compared to the desktop app.
Pretty please consider implementing multi window support where each window has its own tabs and can be initiated on MacOS by using CMD + Shift + N.
Cheers! 