I slice the Monocote on each side of the hinge location, cutting at an angle towards the slot at maybe 45 degrees? This gets the monocote out of the way and leaves room for the pin to be recessed in one step.

I converted to Gorilla glue as I can use the bottle tip as an applicator. After many years of using other processes, this seems simplest/easiest for me. I just push some glue in the length of the slot, then push the pre-oiled hinge in to place. If some comes out during the setting process it's nothing a #11 blade can't remove quickly.