This is just isn't - this stuff will kill you in a 30mph collision. If you saw someone put a baby on the hood and drive around like that would you also say "oh do you expect these people to secure their babies for a one time trip - relax!". Like, it's just not safe. At all.
And the fact that it's a one-off makes it worse, not better - they won't be used to the handling a van this heavy, you will try to come to a stop and discover you're missing a car length - enough to get t-boned by a truck. I don't know why people treat it as some kind of wild and completely improbable incident that just won't ever happen - of course it will! These sort of things happen all the time!
>>not reasonable to expect them to implement a tie down solution that scales to that level
It's unreasonable to not expect them to.