Re: PROPANE HOSE
You can't use that kind of hose on anything that moves regularly. That type of flex hose is for item that are only moved OCCASIONALLY because it will crack with regular movement. Do not run that in place of iron pipe around your truck or one day you'll become one of those food truck fire videos on Youtube.
They use that in homes and some restaurants for the last couple of feet to connect grills so they can occasionally pull them out, but if they get pulled out to clean on a regular basis that is not allowed and will cause a leak.
They do have flex hose that can move regularly for equipment. Google "Dormont Blue Hose"