Could a new attribute be implemented that would allow the current page you are on to be not shown in the list? For example, if there are 10 pages in a category and you are on one of them (it's opened), only nine pages would be shown in the list as the page you are on (that is opened) would not be shown. Sometimes it's useless to list the page you are on, if you are already on it.
Topic on Extension talk:CategoryTree
The attribute could be for example: except=current.