Above the strut there is some space to install the hatch fastener. The fastener must be strong enough that you can lift the hole boat on the airscoop on the hatch.
The backside. On the left side you can see the holes to fix the rudder to the mounting plate. And you can see the counterpart of the strut holder. When loosen the 2 screws from the strutholder you can adjust the holder with the screw very accurate. The holder is adjustable up to 5mm top and down.
A little bit tricky to reach the setup screw, but possible.