If the airline must provide the CRS -
How many and what kind of CRS must be available?
Redistribution of add-on CRS after use
Who puts the add-on CRS on/off the airplane?(Passenger, ground crew, cabin crew? When the travelers change planes?)
Who is responsible for proper use of the CRS? (Passenger or cabin crew?)
Who is responsible for injuries associated with use of the CRS? (misuse or unfamiliarity in an emergency)
Sanitation and maintenance of the CRS
How about children with special needs?