Stackable is a Gutenberg-native block library that went through a major version change from v2 (ugb/* namespace) to v3 (stackable/* namespace) with overlapping support during the transition. Block instances are stored as block markup inside post_content, so pages can carry a mix of v2 and v3 blocks across years of content. Reusable blocks live in the standard wp_block CPT.

SleekView reads post_content across pages, posts, and any public CPTs, indexes Stackable block usage by namespace and block name, and surfaces version drift as a filterable column. Filter to posts still using ugb/* v2 blocks to plan v3 migration. Filter to posts using a specific v3 block to audit coverage. Sort by last edited to find recently touched pages that still carry legacy markup.

Inline edits to status, slug, and author write through standard WordPress update calls. The block markup in post_content stays editable in the block editor where the Stackable controls live.

Stackable's transition from v2 to v3 was a significant rewrite that introduced a new block namespace and a new editor experience while keeping the v2 blocks functional for backward compatibility. That decision protected long-running sites from breaking on upgrade, but it also created a new operational question: which pages still use v2 blocks, and which have been migrated to v3. The default WordPress admin doesn't surface block usage at all, so version-drift audits across years of content require database grep or page-by-page inspection.

Agencies running Stackable across multiple client sites face the same question per client. In-house teams running Stackable on a single site face it across years of campaign pages. A queryable block usage index changes that audit fundamentally.

Filter to v2 pages to plan migration. Surface deprecated block usage before the next upgrade. Track v3 coverage across the site.

Migration becomes a measurable project with a backlog instead of an ongoing investigation. Agencies use the grid output as a client deliverable; in-house teams use it as the migration plan they finally have.