We bring an airbed and put it in the kitchenette area. You can still get to the bathroom and kitchen at the BWV, but the refrigerator is blocked at Kidani.
We stand it against the wall in the day and it is out of the way.
No, a cot does not create a fire hazard unless it is electrical with a shorted out or borken cord that sparks. The room could be wall to wall stuff, but if it has a door to the outside or an egress corridor, it would be okay.
It's just that DVC will not permit over occupancy based on their rules. Cots and rollaways are one way to exceed occupancy. Thus, none of these in DVC resorts.
We had a similar situation with our son and daughter. We used an inflatible mattress in an OKW studio. It slide nicely under the queen bed when not in use.
I am interested in the rental of the aero bed.
I have never heard of a hotel renting aero beds.
This is something we are interested in as our DS 12 wants his own bed .
I think these Aero beds are just left behind by guests and Disney decides to use them. DVC has never offered rollaways and cots to increase the number of sleeping spaces. They have never advertised the availability of these, so I wouldn't count on getting one.