Glum, one man to speak to with `authority` would be the CTP Roger `Dodge` Bailey.
Earlier it was mentioned that you were doing away with the rudder pedals- and using the stick ,by twistingfor yaw control. I think you are going a step too far by bringing to a `hybrid helicopter/aeroplane ` a novel control system. This may be because you have been playing too much on MS Flight sims,and have little ,or limited actual flying experience of how aircraft are controlled,especially helicopters.
As a starter,you need to steer the aircraft on the ground,you need brakes,; you need seriously to look at the `ergonomics` of various manoeuvres that are used in the hover mode such as moving the `cyclic` control,which may have several switches/buttons on it,and then consider the relationship of those contols whilst you now twist the stick; Ones` wrist has only a limited range of movement in certain planes,and whilst using the fingers on the stick grip,you would find it increasing difficult to operate.
The rudder/yaw pedals can be fly-by wire,but they can also serve to give the pilot feedback,can `tremble` if nearing a control authority limit,or a yaw rate limit or a sideslip limit ,which I consider you would not be able to do by using a `twist-stick`. Remember, that the lower speed end of the aircrafts` envelope is where it is operating in a `seat-of -the pants` environment,where one uses one`s senses more than in conventional flight,and control must be instinctive. Remember, pilots who convert to these `hybrids` have/will come from both helicopters and fixed wing,where the basic control functions /responses are largely the same,so putting in another new-concept will make it a higher workload. It is one thing to sit at a desk and play with a computer stick- quite another to strap your backside into a real aircraft ...You may try a PM to `Ospreypilot` who may have some thoughts on the subject,or he may be busy in a hot,sandy place...