Compatibility with custom fields

I started using the “Custom Fields” plugin to better work with unique data I want on each page, some of it in collapse-o-matic menus. However, while the Custom Fields plugin works well with HTML, it doesn’t seem to work at all with the collapse-o-matic [expand] [/expand] tags. Is there a way around this to get them to work with each other?

https://www.ads-software.com/extend/plugins/jquery-collapse-o-matic/