Originally Posted by
fizz57
The non-linearity issue was brought up by FCEng84 way back when the whole thing started in one of the now-closed threads. It is the stick force reversal and instability that are speculations, and came later.
That poster was usually a very reliable and well-informed source. Unfortunately he hasn't posted for a very long time (probably the price for being too well-informed).
A few of us commented on the issue regarding trimming non-monotonic curves at the time. The wise old pilots ignored. So we shut up.