My Kimber is a stock 1911 Ultra carry. Very robust, high quality build that feels super balanced in my hand.
I did a quick check. The boat trailer has cables instead of chains, and they originate from a single central point under the tongue, crossing will only cradle if it lands on it just right. That set up is not ideal, but it has a triple locking coupler that can't possibly come loose without a catastrophic failure.
Travel trailer has the chains originating from the right and left side of the tongue which is the correct attachment. It does cradle exceptionally well, and I do cross them, but it doesn't really matter since it has a solid bar attaching weight distribution set up.
The tandem flat trailer has chains originating from each side and does cradle nicely as long as I keep the chains the proper length. If I leave the chains full length it gets really close to still touching pavement.
The utility trailer only has one chain. I let someone borrow it and they jackknifed enough to rip one chain off.
The jetski trailer also cradles nicely when the chain length is adjusted properly.
As for the math, not had time to look into specifics. I'm imagining scenario similar to the video you posted. A pickup with a utility trailer, chains uncrossed, tongue lip hitting a lip in the road (think concrete bridge expansion joint where one side of the joint is 1/2" higher and the sliding lip of the tongue makes solid contact) while doing 65mph.
Even if the math doesn't prove to be enough force to snap a chain, I still think it will be enough force to do damage. Compared to the tongue getting a chance to be cradled by crossed chains and not hitting the expansion joint in the first place, I still think it's worth the no extra time or effort to cross them. Since jackknifing was enough force to snap one of my chains, I'm guessing the expansion joint scenario math will pan out.