Charlie, I think you could still reduce the stress on the hinge by optimizing your existing struts
position in a way to reduce vertical force to the hinge so that when the spring with hatch is in lowered state, it is pushing more
away from hinge, not just right up, similar to what was nicely shown and explained how to install gas springs by Noseoil in this post -
http://www.tnttt.com/viewtopic.php?f=50&t=60248&start=60#p1100424 I wish you success in your efforts. I hope this helps.