I have started a new Post, because I really do not want, at this point, to complicate this issue, with the Hardware Toe Brake Pedals.
I believe the basic Toe Brakes, differential Toe Brakes and their operation as affected by the rudder, needs to be resolved FIRST, before one can see the "wood from the Trees" and address any Hardware issues.
First Some basics when you are in taxi mode, as is applied by the A2A C172's Accusim.
(1) Taxi using only rudder.. Nose gear will steer in the direction of rudder pedal movement, if plane is rolling.
Nose gear has limited movement. OK
(2) Taxi straight and apply Keyboard TOE Brakes (NOT Differential Brakes).
Both Brakes come on PROGRESSIVELY, over the period of about 2 seconds.
Release Brakes, and they PROGRESSIVELY go off, over a period of about 2 seconds.
This 2 seconds to fully release Toe Brakes is the 1st suspect operation, and may explain the delay in moving after 1st releasing the brakes.
Applying the brakes over 2 seconds may be acceptable.
Taking 2 seconds to RELEASE them is not.
(release filtering need to be faster than apply filtering ? )
(3) If one is trying to turn, and has applied rudder , and then apply Toe Brakes, then the Toe Brakes are AUTOMATICALLY Applied DIFFERENTIALY (to help in the turn -- cool Accusim feature ? -- its not standard with stock aircraft)
Ok so far.
(4) Now, things get a little complex when one tries to INTENTIONALLY apply DIFFERENTIAL BRAKING, when moving ... either with rudder straight, or when in a turn.
(this is what those with rudder pedals may be doing, either Intentionally, or maybe unintentionally because they do not apply EXACTLY the same pressure to both Left & Right Toe Brakes)
Basically, there appears to be a whole slew of Logic, trying to determine what should effectively be happening to the Brakes, there are delays, and there are what appear to be race conditions.
Suffice it to say, when looking at a Custom Gauge, that shows Axis input, vs what is being applied to the plane by Accusim, it is very suspect, and one can imagine that a lot of the issues being reported, and due to this potentially suspect logic.
If you are interested in looking into this, you might like to get this Free FSX addon, and see what your system is really doing.The Axis Utility program I used is called AxisViewer.
http://library.avsim.net/download.php?DLID=165339
Install addons at your own risk -- especially FREE ones !!
It now has me curious, so I'll probably jump into it, and spend a few hours over the weekend, trying to determine exactly what is happening, and why.