JoinUp Membership registers a signup custom post type (typically joinup_signup) and writes per-signup configuration into wp_postmeta with keys like _joinup_level, _joinup_status, _joinup_source, and _joinup_renewal. Membership levels themselves are usually a taxonomy or a second small CPT.

The default admin shows signups as a vanilla CPT list, which means level and status only appear as columns if the plugin author added them via manage_posts_columns. Most JoinUp builds don't expose all relevant meta as columns, so finding signups by level + status + source means clicking into individual posts or filtering by category. There is no joined view of signup plus level plus source.

SleekView reads the joinup_signup CPT and joins the relevant _joinup_* postmeta as first-class columns. Inline edits go through update_post_meta(), so any hooks the plugin registers fire on save. The result: a signup-centric workspace that doesn't require opening individual posts to see status or level.

CPT-based membership plugins like JoinUp inherit the strengths and the limits of WordPress' default object model. The strength is interoperability: any tool that reads wp_posts and wp_postmeta works, including SleekView. The limit is that the default CPT list table only shows columns the plugin author chose to register, which usually leaves most of the operational data invisible until an admin clicks into individual posts.

For a small site that's fine. For a site with thousands of signups across multiple levels and acquisition sources, it isn't. Marketing can't see source attribution at a glance, ops can't bulk-flip status without scripting, and support can't answer a question about a signup without opening its edit screen.

SleekView turns the _joinup_ meta into proper columns, joins on the indexed post_id, and gives the whole CPT a queryable workspace. The result is faster lookups, faster bulk operations, and a much shorter feedback loop for the teams that actually run the membership program.