That sure seems like an unprofessional way to leave that. On our new trailer, we got a tee with a plug in it about midpoint ahead of the wheels. We had to order the exterior BBQ package just to get the quick connect fitting so we said no thanks.
We wanted a QK fitting at the end of the trailer next to the rear door where the kitchen is. Here is a pic of what I did and a pic of the QK adapter and mods for the hose for our Coleman Roadtrip grill. It took 2 trips to Home Depot, 1 to Ace Hardware, 1 to Home Harware and 1 to a RV parts store to round up all the fittings. Pain in the butt finding all the misc. pieces for some reason.
On the trailer, I used electrical unistrut brackets (Home Depot) and special isolating pipe brackets from a plumbing wholesaler which have plastic insulators to prevent corrosion between disimilar metals (important on gas lines). I used a 10' standard LP hose to extend from the original tee location to the rear of the trailer (affixed with tie-wraps). The QK fitting is now in a nice accesible location.
The Coleman low pressure adapter modification works really well and we get better heat output when 2 burners are running. No more fiddling with the tanks at the front.