ARS 5540 not for snakes UNDER 400 grams?

I have one ARS 5540 for my hognose breeding. I have been using it for two years with no issues. I like that I have room for more enrichment for them. I was about to purchase another one when I saw a warning not to use it for snakes under 400 grams. Only one of my snakes is over 400 g, the one I feel is maybe a little cramped in the rack. Anyone know why it says this, as I would hate to put my snakes in danger? https://www.arscaging.com/ars_caging...el=5540-Hybrid

It could be that the removeable top's spacing for airflow is a bit larger than a hatchling rack so there's an escape risk or the animal can wedge into the space and hurt itself. That's usually the most common issue for things like this.
I don't own the ARS system to tell you the reason exactly though.

That would be my guess as well- there's one or more small openings that a tiny snake can fit thru or get injured in. I'd take their word for it.