Your right on that javaseuf, the table top models that use a screw on disposable bottle normally have the regulator built into the burner control and they would be difficult to modify to operate on the low pressure line on the trailer. My Porta Chef is a 20,000 BTU free standing unit.
Thank you to all who replied to my question. My BBQ is one of those with the regulator built into the temp control. I was curious to see if some ingenious soul had found a safe way to convert to low pressure use--safe being my primary concern here. I have been working with natural gas (not in the customer service end, but with higher pressures ie 5 psi up to 600-800 psi for 36 years), so am quite aware of what may happen through lack of adequate planning.I will be looking at the extended stay adapters which are commercially available instead.