It seems like throughout the years. people wanted to do aftermarket add on bunk beds. DIY type stuff. I am guessing folks wanted to bring kids or grandkids. Or bragging rights.." My trailer sleeps 25 people ". But Airstream has offered bunk beds as an option not too long ago. They might be different than the other two versions that I mentioned.
I took out the homemade attachments that came with mine. It didn't seem safe, and my kids were already too big. It looks like you would have to lift the kids in and out of the bunk beds. And my thoughts are, that a trailer gets rank with too many people in it, not to mention over taxing fresh water and waste tanks