Has anyone ever suggested having deceleration as as separate parameter from acceleration.  A lot of the factors that go into choosing an acceleration don't apply for deceleration such as friction, weight, etc. It would make tuning a little more complicated for some people, but in the case of my machine it could result in a measurable improvement in performace.

You are the first one to ask for it and I can tell you that it is not going to happen anny time soon There is a ton of code in Mach3 that is set up to work with the same Accel and deccel. Sorry