So I made a boat dispenser and they went thru the floor. I have a video.

Questions about the video: the slabs are for the boats to not get stuck, it is the same with full blocks; I saw that it happens when I turn on the water and one goes right and 1-3 go thru the floor

https://files.fm/u/gdpdfrezs (the video is 300mb)

Btw I have carpet mod with fabric and sodium in the video but it is the same for vanilla

edit: After the test I came to the conclusion that Carpet mod actually helps, because the boats don't get stuck in the water elevator and it doesn't have to do anything with collision because they just go thru walls