A frame bike carrier

I have a Fiamma bike carrier that I used on a Jayco Freedom. I was only able to do this because I specified the gas bottle be fitted in the boot. The forward bike could be damaged by the spare on tight RH turns, due to the offset wheel on the back of the Pajero.
The replacement caravan that is being built will have both the gas bottles and the bike rack on the A frame, however the A frame has been lengthened by 50cm to accommodate both. As the gas bottles will be forward of the rack, there will be no interference with the bikes on turns.
After looking at online photos of Jayco Swans, I am confident that it would not fit without removal of your gas bottle and even then there may be conflict between the carrier rails and the support arms for your forward deck.
The width of the carrier is 33cm and to this must be added an allowance for the pedal at back. It also means that you would not be able to access your boot without removing the rear bike or open out the forward deck without removing both bikes.
Good luck as on the front is the best location and my bikes have done over 40000km on the front of the last van and will be continuing on the next van.