As Craig has said, if you want ‘S’ curve then you need to be using a different software / planner or alternately wait for it to be incorporated within Mach4 (which could be a long wait).
Back in the days of Mach3 – Art developed the Tempest trajectory planner which did incorporate the ‘S’ curve and it was, at that time, intended to become Mach4. However, it was later decided to develop Mach4 from the ground up and the ‘S’ curve was subsequently dropped from the planner.
Art then went on to develop another trajectory planner software ‘Auggie’ which does incorporate the ‘S’ curve and this software can be downloaded from Art’s website
http://www.gearotic.com/index.htmlAlthough Auggie was intended as an addon to Gearotic Motion I believe it can be run as a stand-alone program. If you have the time then check it out.
Tweakie.