The frame has a cutout to place a gen in the compartment, but the upper side is covered by the flooring and the lower side by the chloroplast. If a gen is installed, they will cut the floor and the chloroplast to expose the opening. Pretty routine operation, if the installer knows what to do. Sometimes, the bracing has to be modified or moved. I think Onans come with a template to make the floor cuts.
2016 Tiffin 40QBH
2005 36TK3--retired, but it was a good one
2017 F450 KR