Hi,
I think it would be a good idea to enable the customisation of the scroll bar for repeating groups. The standard OS ones make applications look dated. I was thinking something like the example at http://manos.malihu.gr/repository/custom-scrollbar/code-examples/responsive-custom-scrollbar-with-css3-media-queries.html or the scroll bars in the plugin section of the bubble interface.
You could enable customisation via the style section to change colour, roundness etc.
I know you can do this for webkit enabled browsers like Chrome and Safari by adding some code to the header but IE/Edge users endup with the standard OS scroll bars.
Thanks!