Is this possible? I had been struggling as I thought I was bound to PropertyPanels which explicitly reset the width back to the width of the parent, but then I realised in the add panel method it’s just asking for a Component, so by the time I went to sleep last night I Was inheriting from Viewport in my component class (the object to add to the concertina panel).
However I noticed upon moving the panels title bar to expand it, the viewport was reset to the width of the parent, just as the property panel did, and I did not see either of the scrollbars.
This enquiry could also be answered by how to implement a horizontally and vertically scrollable component into a concertina panel.