Interchangable Drag+Drop behaviour between Tree Tabs vs Tabs Bar, Bookmarks Bar and Links
I'm not sure how easy this would be to implement but at the moment when you drag a tab from the Tree Tabs panel to the Bookmarks bar (as in to save a bookmark in a specific folder/position) the tab is lost. The result is a new window is created which goes to a new tab without loading the dragged tab. The Tab bar will still have the tab but actions such as closing the tab from the Tab Panel will have no effect. This is likely due to the browser tabs order being desynchronised again.
Conversely, nothing occurs dragging from the Tab bar or Bookmarks bar to the Tree Tabs panel. Where the expected behaviour would be re-arranging the position of tabs or opening a bookmarked tab at a certain Tree Tabs position or under a certain group. There is also another case where a link (eg. from the address bar or a text box or a webpage link) dragged to the Tree Tabs panel will not be opened and nothing will happen. Like previously, what you expect is that the link will be opened at a certain position/under the chosen group depending on where you dragged to. With these cases, Tree Tabs should detect what is being dragged (an existing tab or a simple text link) and behave fittingly.
Sorry if this is poorly explained, I will re-clarify if needed.