The new dorel quadruplets (guide 65, eb xrs65, etc) allow rf to the top of headrest or 40" even though the headrest is not reinforced and the vast majority of 40" kids will be above the shell. There is eps foam in the headrests. On the test bench, there's presumably no front seat or console to impact on rotation. I have some mild concerns about how this would play out in the real world. I understand that it's "safe" in the sense that it complies with the spec but I can't help but believe a taller shell would be safER. Please discuss and share your opinions.