I have created a problem for myself, and would be grateful if anyone can help me around it.
I have changed the basic WP setting of the number of post per page to 50, by adding this in my theme.
$query->set( 'posts_per_page', '50' );
However, it overwrites the "List Category Posts" post count command.
ie: numberposts=x will show 50 posts no matter what number I use for x.
I needed the larger number to get more search results showing that the WP default, which appears to be 10, with any more on more pages.
But I also want to control the post numbers when I use "List Category Posts"
I amended my post per page so that "WP Custom Search" would return more than the default per page, as I needed all results to show, some of my results need up to about 50.