I do it all the time I'm not sure what you are talking about. I use Tree Style Tabs extension (obviously), so maybe the feature is coming from there? You can

I do it all the time I'm not sure what you are talking about. I use Tree Style Tabs extension (obviously), so maybe the feature is coming from there? You can definitely drag and drop a tab from one window to another, target window can be in a different profile. You can select multiple tabs with SHIFT and then drag and drop them to the other window, no problem.