Scrollable collapse list with limited content rows

Great plugin, very useful and appreciate the development. Is there functionality or a way to have a scroll bar on the right of content list that may be too long?
Perhaps limit the content to 10 rows and then scroll for the rest.

Secondly, the read less at the bottom is not working for me when copy pasting from the example you have. Is that not tested when using another shortcode within the expand shortcodes to have ‘Read less’ at the bottom of the list to work?

Thanks in advance!