Chorus plant cullface does not work against chorus flowers or other chorus plants

The bug

Chorus plant blocks explicitly define cullface arguments for faces which end up being obscured by other chorus plants. However, the game doesn't actually do any culling despite this between two chorus plant blocks or a chorus plant block and a chorus flower, and it only works against full, solid blocks. This means that the cullface arguments for the top face and four side faces can never be seen without the use of a debug stick.

How to reproduce

1. Create the arrangements of chorus plants shown in the screenshots

2. Enter Spectator mode

3. Fly into the plant and note the region in which two plant blocks meet

Expected results

As the chorus plant models explicitly specify that these faces be culled for these exact circumstances, they would in fact be culled.

Actual results

The game makes no effort at all to cull these faces, instead rendering them completely unnecessarily.