Containerise loading freight into passenger cabins

We are now a year into the pandemic and its time to better organise the loading of freight into the cabins of passenger aircraft.

There needs to be developed a container that can get in through the passenger door, or the emergency exit door opposite. Preferably in a bit less than 1/2 cabin width size, leaving space for passage down the middle.

After all every airport have the equipment to load such containers, daily in use to load the wheeled carts that contains food, drink and duty free to be consumed and sold onboard. In practice they could be seen as small containers.

One could also do with a track system that would be fastened to the mounting points normally used for seats, to easily move around and lock in place the cargo. 

Maximum weight would be 5 passengers at 70kg each plus the weight of the seat lets say 50 kg wich give a maximum weight for each container of 400 kg. for a 3+4+3 seat width plane and 2 container wide. sample a 787 or A330. That should leave at least 350 kg for freight when one deduct the weight of the container.

The containers would need to be developed in different sizes. Starting with the A350 and the 787 but also potentially for the 737 for shorter shorter distances and more time urgent freight. The recently faced out A340's would proably be better to convert with a cargo door because they will proably not come back to passenger services. The A330 would also be a candidate if one was thinking of bringing it back after the pandemic. Who knows. The concept could become so popular that some freight shippers would like the airlines to stay with the concept.

The whole conversion should be targeted to take no more than 1 to 2 days, each way.

Such a solution would give airlines, and shippers, a more even footed approach to the vagaries of the passenger business that have come up in the later decades.