So you are not running the propane in an on board tank then?

I have had 2 of them burst an onboard line in my face, one at Florida Jets in 1998 (my plane) and a KingCat burst a line the last time I went to Florida maybe 2 years ago.

But I think these external systems are fine as you do not have the propane under pressure in a hot line for a long period of time.