Admin section: collapsible pages list

I’ve got a CMS function going with pages, children, and children of children pages, and they are starting to present a real time issue in navigating to update a particular page in the admin. The pages are listed with all children showing at all times.

Is there any plugin (I’ve searched, but all plugins with the word collapsible are for the front end, not admin) that will collapse the children of pages listings in the admin list of pages?
I know that’s getting very particular, but anyone with a lot of pages in a CMS version of wordpress will probably have thought of it.
thanks
JSC