Honestly, I had never used an ion panel before, but this question intrigued me, so I went looking. It seems, and you can see on this Codepen: http://codepen.io/anon/pen/JGwJKv?editors=1010 , if the content is too large (if you try to resize the browser window to very small), this will not show. Against ion-content , which will add scrollbars and allow you to use ion-refresher and some other parameters (clicking on the scroll delegate, etc.).
So, to be honest, I never came across the need for such a precedent, so I probably would never have used an ion panel. The lack of documentation about this seems to suggest the same ...
source share