I would also like to see this addressed.

You can't sync tab groups or workspace tabs, and you can only open tabs from other devices 1 at a time. There isn't even an "open all tabs" button.

These are features chrome, firefox, and edge have had for a long time, and a feature I see requested in opera's forums going back to 2020.

I have not seen responses from opera on those forums, or any hints of the feature being added to Opera/Opera GX.

Because of how workspaces are handled, tab session extensions have trouble as well. They do not recognize the workspaces as separate sessions/windows to allow for automatic syncing.

For now, the only options seem to be manually transferring tabs 1 at a time to another device or using a 3rd party tool/extension to manually transfer them in bulk.