Thank you everyone !
If you're interested in playing around with/using the guard,
here's one of my earlier wip with just him.
If you'd like to see the inner workings of the button gate,
here's a mod that shows the inner working of it. While it's extremely straight forward, I did run into a problem because the gate would push on the cube it's resting on, releasing it before the end, so if you want to make a button on your own, you'll have to tweak the weight of the gate, and how far the below cube reaches.