To answer a couple of questions and concerns I've seen since my post.
To adapter to a standard lp system would be easy with an adapter hose. Any that converts your propane to the round connector for a 1# bottle will work. To tie into a system after the TC regulator would be a bit more troublesome, but could be done.
As far as putting a pot on and boiling water, should be able to do it but would use more propane than a little side grill.
I've been carrying the 17" with the griddle in the normal position in the back seat for the last 3,000 miles, some of it rough road. No bending of the sheet metal at the four post. No smell even after cooking salmon which is one of the smelliest things I know. We just put a Blackstone cover on it before sliding it into the little wooden box sitting in the back seat. The side towards the door of the box is open, but we haven't noticed any smell, even after getting in the truck at the end of a hot day.
One of the key things to the griddle is not cleaning it too well. Usually after I cook, just scrape then turn off. When I turn it back on for the next use, just scrape again, wipe down with a paper towel then light coat of olive oil. Things like burgers are the worse, but still not a big deal.
Cool down for storage takes about as long as required to eat. I have put it up within a couple of minutes when we had a storm roll in, just didn't put the cover on it until later.