here's a drawing of what I'm thinking, it can also look like just a flat bar with an edge welded to it near the pivot, that stops movement just past the center point. in the image they used a pin as a stop, same result, different ideas. The flat bar thing is easier to make up in your basement without a milling machine.
I think if something like that could ride along beside the struts it would be just a matter of giving it a little push to lock or unlock, and it would be stable even with weak shocks.
I like that a lot more than a prop rod , but might take a little though to mount it and position it so it isn't interfering too much..
maybe a spring with an inch or so of compression could be added to make the latch pop the first bit,, then you'd compress the spring as you closed the hatch?
I think it's an interesting engineering problem that could be solved with a 12 V l linear actuator.. but that gets a little too complicated.. in theory a linear actuator ( or a pair) worth under a hundred bucks could automatically open the hatch and close it too , it would not put pressure on the hatch when not being actuated, removing the 24/7 pressure entirely on the hatch and replacing the gas shocks.
some new SUVs have a sensor where you wag your foot and it opens the hatch. kind of similar..
it might get stuck and self destruct if blocked mechanically.. and basically that's just a half baked plan..