My guess is that the second awning is model specific. On the RL the second awning is mounted on the Living Room/Dinning Slide, probably neither slide on the FL is large enough (just my guess). I know the RL the power plug and control switch are installed at the factory, so it could be added later without a problem.
Michelle & Ann
2018 Chevy 3500HD Crew Cab High Country DRW, D/A, 2016 RW39MB, Dual ACs, Auto Level, Auto Sat Dish, Stack W/D, King Sleep #, 17.5" Sailuns w/Disc, MORryde IS & Pin, Comfort Ride Hitch, 5.5 Onan, Res Fridge & Induction Cook Top