The following may be a bug report rather than a feature request. It depends on whether the desired behavior I describe below is already meant to be in Photoshop or not.
I sometimes find that I have a number of images open in Photoshop at the same time. I prefer to keep them in tabs so that it is easier to navigate between them as I work. I will often drag a tab, say the most recent one I have opened, from the right side of the panel over to the left just to keep things orgnaized in a way that makes it easier, once again, to find my way around.
I have noticed that it is difficult to drag a tab from the extreme right of the panel (which is quite wide on my screen, btw) to the left. What often happens is that my mouse cursor breaks the top or bottom plane of the tabs row, and when that happens, Photoshop thinks that I want to un-dock the document from the tabbed area and make it float. When I drag it to the place I want it to reside, back among the tabs but at the far left, Photoshop instead drops it back at the far right.
The only way I can move the tab is if I am very careful not to break the top or bottom plane of the tab row. So I might have to drag something 2500 pixels to the left, while keeping it carefully in a vertical space that is probably only 30 pixels high. That is difficult and annoying to do.
Please change the UI so that when a user drags a tab from the tab row, breaks out of the tab row with their cursor, but then reenters the tab row at a different horizontal position, not only will Photoshop drop that document back in the tab row, but it will respect the horizontal positioning of the cursor and reorder the tabs with the dropped tab landing where the cursor was when the user releases the mouse button.