SUMMARY It would be a nice feature to be able to drag the window by clicking and holding any area including the video area but without replacing the current click functionality.
by the way, it is possible to move any window (including haruna) by pressing Win key first, and then clicking wherever you want. But, yes, just for consistency with "raw" mpv it would be nice to have possibility to enable (and, obviously, disable) this.
The 1.2.1v cannot be even dragged from a toolbar. Some people are really accustomed to this preference. Especially ones with multiple screens.