One one site this extension brings the functionality of workspaces (like Edge or Vivaldi have natively) to Firefox. And that's great. On the other site there is an anoying behaviour and a backup issue. The anoying behaviour is: Every time I shift a tab into a workspace or into another workspace this other workspace is focused. That should be selectable. I don't want to leave my current workspace when shifting tabs.
The security issue is: There is no way to backup the workspace set like in SimpleTabGroups for example. If Firefox crashes or the start options of Firefox are changed, the workspaces are lost.
I work with Edge in business and more and more in private life because workspaces are so well integrated. I don't want to miss them.
So I hope this extension will be modified soon.
Wish you all the best and good ideas.

If you close the browser it didn't remember the tabs that were open. I wish that it would have a feature that let's you change workspaces with keyboard shortcuts.