The "M" -60 has the Martin-Baker seats that stroke for the crew chiefs. The pax are still hooped, with folding seats.
I think this is precisely why we need an O-7 approval for seats-out pax flying. If we do a hard landing, or worse, the pax are screwed. They'll have 0 absorption from the impact, vs us and the crew chiefs.
The hawk is designed to crash vertically (well not really, but really). It has a lot of built in protections to allow for survivability of the crew. Not the case for lateral/longitudinal impacts.