I understand the problem and how irritating it could be on a notebook to scroll the pane. The solution would require a low level mouse hook, because the focused window receives all mouse messages. I tend to be careful with these low level heavy calibers.
My long term idea for this pane was to get rid of the scrolling altogether and automatically close panels that would not fit. Something like the panels in Outlook. On large display, you would still see all; on a small one, the application will try to keep the last used panels open and close those that do not fit.