Masterpress 1.3.6 is a compatibility release. It resolves an edge case with shared fieldsets not working for MySQL 8 when the fieldset is limited to more than 1 post type or taxonomy or excluding any post types or taxonomies.
MPFT_RelatedPostType :: count()
Return the count of post types selected in the UI. Since this overrides count the number of post types can also be retrieved by calling count directly on the field object.
Note: This method is intended for internal use and should not be called directly.