Currently, the light blocks in the inventory that have different lighting levels glow with the same intensity (even with 0 level):
https://youtu.be/I33eF9vvEHA

it would be more logical if the level of dynamic light depended on the level of item in the inventory.

Trying to fix this, but just for posterity, Java decided to become as cursed as possible.

Executing state.getLuminance() returns 7 as it should, but if the entire method is executed it returns magically 15.