Pivoting trailer gate on multiple axes

I am currently trying to design a rear gate to retrofit to an existing caged trailer (similar to image 3), with the goal of having a system where the rear gate can pivot down (on its bottom edge) to form a ramp, or from either side so that it can swing out of the way to the side.

Currently I have the following design mocked up (not to scale): images 1 & 2. In these images, parts are coloured as below:

• Black: Existing trailer body
• Grey: Hinges with removable locking pins, as seen in image 4. Horizontal pins would have some kind of extra or spring loaded locking to avoid loss during vibration. This part should be straightforward.
• Blue/light blue: Ramp and attachment points
• Yellow: Gas strut/damper or hydraulic ram (this is where the issue arises).

The current issues I am facing at this point:
– How can I attach and detatch the strut from the bottom of the rear gate to allow the gate to swing open sideways, while reducing the risk of sudden release? I am thinking of some kind of mechanism where the strut slots in to the rear gate section.

The strut appears necessary as a method to dampen the rear gate movement, as it will likely have significant weight.

My end objective here is to be able to have the rear gate function as a ramp for loads up to approximately 500kg, as well as being able to swing out of the way for loads that are simply pushed off the back of the tray (e.g. gravel, rubbish dump runs).

Ground clearance ideally should not be reduced (below axle level), and a dependence on electricity should also be avoided.

So, my question is, how can I safely and efficiently detatch this strut to swing the gate open sideways with the above design, or should I consider an alternative design to achieve this?