block culling rules doesn't apply for full_block custom blocks where its format_version is 1.26.40

The document offers a example of custom glass, which uses the

{"bone": "block", "cube": 0, ...}

This may imply a glass block, approximately a block using “geometry.full_block“, has a bone named “block” to use face culling.

In that case I tried to build a custom spawner and turned out it rendered every faces in game.