Do i really need a TT with enclosed underbelly?

Does everyone else with an enclosed underbelly trailer have their propane lines run OUTSIDE of the enclosed underbelly? I assume they did it this way on my Coachman Captive 265EX so if the propane line springs a leak the propane dissipates into the air instead of building up in the underbelly? All of the connections to the main propane line are also external to the underbelly which would make sense since connections are where leaks will most likely occur.

The external propane line makes it a real pain to remove and replace the corrugated plastic underbelly panels for sure!