Thanks for the thread, it was a good read.
Obviously, there is no definitive answer. I'm WAY more concerned with a rollover situation than a strapped in child's restraints failing and them hitting their head.
I think all the people citing the similarity with Jeep Wranglers are correct. If having a padded rollbar was an issue, massive lawsuits would have put that vehicle out to pasture decades ago.
Of couse, my opinion is based on a 4 point bar without an added crossbrace (used for harness or camera mounting).