Further meditation on specialist safety dog transport crate suppliers:
Found a third credible supplier. Yet again, their appropriately sized crate doesn't fit in anything carlike. In fact, it doesn't even fit in full bore SUVs. It's got a doable footprint, but it's just too damned tall to fit in anything but a full size cargo van or pickup truck.
HEY DICKHEADS. THE DOG DOESN'T NEED TO STAND UP AND RUN AROUND. IT NEEDS ENOUGH HEADROOM TO GET IN THE DAMN CRATE AND LAY THE HELL DOWN.
Also just for funsies looked at a supplier of police K9 back seat inserts. Brief summary: Unsafe for the people in the car, unsafe for the dogs, renders the vehicle utterly unusable, only available in Explorer, Expedition, Tahoe, Suburban. Taurus, Caprice and Charger forces can GTFO. Naturally requires drilling random holes in sheet metal to put crappy cheese grade mounting bolts through. Typical of all police hardware I've ever seen.
Found some actual independent crash testing of the crate we have been looking at for the Ascent. The tie down straps on the rear shear off the cage, but that looks intentional to my eye, to allow the rear of the cage to deform in what is clearly an energy absorbing manner. It's clearly intended to be and performs better when mounted tight against a load bearing partition (seatback or rear gate, both of which we intend to be the case)