Have you ever done built-in furniture that adjoins the shadow gap in the cealing?

Cause I have and after seeing the results it doesn't seem worth it the extra cordination there's gotta be. This was supposed to give the illusion that the furniture goes above the cealing (which it actually does, like 4 cm above). but the space is so damn high that it is almost not visible to the naked eye.

In case is not clear, this furniture goes from floor to cealing.