@leocg Opening multiple windows and managing that with window switching is too much hassle. Workspaces seems fine, i will start using that for longer term saving of some topics.
With tab islands and workspaces while actively pausing and re focusing them introduces alot of unneccecary juggling. Like, actively switching between boxes, you dont really close them and put them away each time you look in another.
What im suggesting is a non submenu workflow. Navigate to left plane - open menu - manage workspaces - add more., edit.. Not what i want to do constantly and then end up in workspaces i have not filtered out junk.
i actually used "tab saver" addons before most of them bugged out or got broken.
when researching lots of subjects in a topics and lots of topics i effectively open lots of tabs before i read in them at all... And many times.. Those initial tab openings can lead to new ideas to research..
just right clicking the tab, "color sub meny, yellow" ads an easy, effective and quick cut point.. Later, when reordering tabs - like tab 54 moved next to tab 22 and tab 24 and 25 exited, because they are good together - would be simple..
Can create workspaces, after that 
