Is that a safe assumption - that the displacements will be large enough to give adequate feedback? The actual wording is:-
(definition of conditions) the slope of the curves:-
(i) control force versus speed, and
(ii) control position versus speed, must be zero or stable.
(The interpretative material then says that displacement must be demonstrated quantitatively, but force may be qualitative).
Interesting also to note that JAR-27 (I assume that FAR is the same) doesn't actually express any preference for force or displacement except in the hover, where displacement seems to be the player.
G