Similar Models says that you can change a rating by 1. However, drone sizes seem mostly trapped by body ratings. The mitsuhama cyborgs seem to be exceptions, but I wanted to check.

Can you swap the body rating via the Similar Models rule? If you do, does it change the size of the drone? Can you get a Body 5 for a drone?

I don't see why you couldn't swap the body rating via the similar models. X company could have a reputation for building their drones to really take a beating without breaking down. No need for an increased size for that.

Similarly I see no reason that 5 would be the max body for a drone.

Same here, especially when Arsenal describes large drones being as big as a small car at the larger end of the scale, and the two listed subcompacts have a body of 8. Considering that, makes me wonder why the Nimrod, Steel Lynx, and Crimson Samurai have only a body of 4 when they're large drones designed for combat. Would think a 5 or maybe even a 6 (particularly for the Nimrod) may be more fitting.

I would definitely allow it, same for Micro and mini drones as they are just a bit more robust for example.

Makes the Ferret VERY useful with 9 slots for modifications.