I was closely associated with the S92FBW and CH148 flight control development and would like to weigh in on a couple of speculations.
It would be very difficult for control margins to be an issue. First, more than adequate control margins were demonstrated through the full flight envelope, which included both steady state trim conditions and extreme maneuvering.
While the controllers are indeed passive unique trim design, the CH148 incorporates an envelope cueing system, which provides both aural and visual cues to control margin encroachment. The most common reason for activating these cues would be if the aircraft was being operated outside of the operational CG envelope.
Some argue that proportional control position feedback is essential to safely operate, but there have been frustratingly too many accidents where pilots found themselves outside of CG but didn't recognize control positions being near limits. For that reason, cueing would be an improvement. Upon weight on wheels, the FBW system controller converts to a proportional controller - valuable during slope landings, but the cueing system excelled in warning the pilots nearing limits so they can have enough control remaining to recover off an excessive slope.
The autopilot uses very little control envelope, so providing proportional feedback is really of little value except to show it is doing something. Further, I would defy anyone to be able to simply look down at the cyclic position and tell me how much control is remaining. You know it when you hit it, but you can't really tell when you're 10% from the stop.
A couple other tidbits:
The controller configuration is 2 axis center mounted unique trim cyclic, floor mounted unique trim pedals, and conventional, trimmable, displacement collective.
FCC architecture is "dual-dual-triplex". There are 3 FCCs, each FCC has two lanes (either one can operate the servos). Each lane has dual processors, and they incorporate dissimilar software to address common mode failures.