It's free. Tabs Outliner did a good job to dealing with tabs management.
And I think someone should make this solution better.
I have the same problem like other users.
so I build an alternative, because I have been struggled for a long time.
It's Link Map, and open source on Github, supporting import from Tabs Outliner.
It's available on:
Chrome Web Store
Edge Web Store
Customer support service by UserEcho