If this extra connection is on the high pressure side of the RV's regulator, then you can add a high pressure hose to virtually any gas grill. I made that mod on my last TT and it was great!
You'll have to get the numbers off the quick disconnect to find a properly matching connector. Then the proper hose to handle the 150+PSI that is in the bottles.
TT 2015 19RD "TheJayco"
TV 2003 F-350 "Montblanc" - Housebroken chore truck
Sitting in The Cheap Seats.
And proud of it!