I always need to pass a low bridge to reach the best sailing area. The bridge is 6 meters above water.
With the sail down, jib rolled, and outboard running. I just tie a line from the forestay down on a small pulley on the front crossbeam, then back to the main sheet hook. The main sheet is fully pulled and cleated when the mast is up. When I get close to the bridge, I remove the forestay pin, loose the main sheet to lower the mast. After passing the bridge, I pull the main sheet to lift the mast up again, and put the pin back in the forestay.
I attached a video of me passing. I don't lower it too much to prevent damaging the mast base. I hold it just to prevent swinging on one side of the boat.
https://imgur.com/gallery/Ja4OZUY