I am creating this question both to answer it for myself, but also to help others who might find the same issue, as I cannot find a single article about this online.
I have been using the below code, within the wp-config.php file for some time now, but have only recently noticed it doesn't work universally - it only works for 'posts'. I would like to enable the same setting for both pages and custom post types.
Does anybody have any information regarding this?
/** limit post revisions to prevent db bloat */
define( 'WP_POST_REVISIONS', 5 );
In my installations it works universally. This discussion confirms my experience: http://pods.io/forums/topic/revisions-support/