I've encountered issues with the behaviour of the sidebar widget, with it not being able to collapse properly when changing screen size. I think this might stem from the sidebar size only being able to be adjusted on a pixel basis as opposed to the percentage option.
If I were to adjust the whole widget in the 'style' pane to pixel sizing instead of percentage, it does collapse properly however the widget would remain the same size regardless of the device screen you are viewing on (appear large on smaller screens, small on larger screens).
I would like to propose enabling percentage sizing on the size of the side pane, and perhaps having a setting that allows you to automatically completely collapse the widget without playing around with the size values.
I have attached a recording as well of the behaviour of the widget.
