I think the point people are driving at is that it doesn't actually test those edge cases you mention, because it still doesn't map to human physiology. That change in expansion or penetration doesn't correspond to what a bullet does in the body of a violent human. No matter how fat or cold or hot they are. It just... isn't data. It's a carny trick that presents well.
It's unfortunate that clear gel even remotely looks like organic gel because it invites comparing the two. Which is about as useful as comparing the expansion/penetration numbers in a block of ice. If that's wrong I'm happy for someone like DocGKR to clarify.