Falling though a Cushion with Lava Bucket

Steps to reproduce:

1. Go into any world with experimental and enable “Drop 3 of 2026”.

2. Place a Cushion on the ground.

3. Sit on the Cushion (Do not Crouch).

4. Look down at the Cushion and place the lava on yourself.

There you fall though one block; this can be used to make secret bases. This however is a bug and is probably not as intended for the Cushion to work.