I am doing a 4 ft or 6ft, or 8 ft) deck, mainly for a covered area grill/smoker and a spare tire mount and access to roof like an old train
It is a pain now using back door when raining etc and the saved inside space from tire/grill is worth the trade off
I am still contemplating the fold down approach and have made a couple hinges and sketched some folding scissor arms etc...
we will see how this spring goes
Legs are not really an option for me, at most campsites we have the "deck area" over water or over "nature" due to increased overhang compared to most
smaller RV spots we use, we regularly fit in 25 foot spots, with aor 10 feet hanging into space
I will tie the deck into the roof and wall on both sides, triangulation is your friend ;)