In reply to https://jan.boddez.net/articles/conditionally-display-innerblocks. Neat Gutenberg trick: you …

Neat Gutenberg trick: you can have a block accept (and store) InnerBlocks, yet still employ a server-side render callback in which you can run all sorts of logic before returning … the block’s “static” contents.

Works for things other than InnerBlocks, too, by the way.

The trick is $block->render( array( 'dynamic' => false ) ), which returns whatever was saved in the editor. And that can still contain dynamic content, by means of InnerBlocks.