I bought the MFSSB recently and am trying to find good settings. This seems like a good thread.
About the deadzone when transitioning:
What I found out is that if you squeeze a thin piece of cardboard in between the axis head (the round "mini wheel") and the actual force sensing sensor (there really is just a very small gap) you can eliminate the deadzone for the transition between the displacement and the force sensing part. Perfectly sine waves are possible. I use two blade springs on pitch, on roll one is enough.
(Will post pictures asap)
I played around with different blade spring combinations and it is a bit of a chore because you have to dial in the axis i.e. calibrate back to the center afterwards using the two screws at the side.
I also played around with custom axis curves in DCS, most notably the very first slider which helps to minimize the deadzone.
Still not completed happy with it but it is promising and the cardboard mod seems to have helped a lot.
I also have to get used to the forces needed here, currently I use values of about 20 on pitch and roll. If I turn it up my arm fatigues quickly (and I would consider myself quite fit I have to say). Coming from a full deflection stick with soft springs this is lot to handle.