Waste chute heat loss

Hola class!

I was about to print out this waste bin mod (no affiliation) to collect waste and also to help mitigate heat loss from the waste chute.

H2/P2S/P1S Poop Chute - Free 3D Print Model - MakerWorld

A comment in there said that the P2S has an internal flap that closes during printing to prevent heat loss. I can't substantiate that claim via the wiki and was wondering if anyone here has a definitive answer.

Does the P2S waste chute have an internal mechanism that closes to preserve heat?