Besides, when I have him out in the open or trails I like having two hands on the reins. I already tried stopping him with one and it didn't work too well :')
Snaffles only ~really~ work well two handed. They aren't made to have any particular leverage or function one handed. Western bits made for neck reining don't use the corners of the mouth, they use leverage at the chin and roof of mouth for 'stop', even one handed. They should always be slack when not in use though, or they are too severe. They aren't comfortable on contact, by design.