If one has JMRI, just use the speed curve, rather than 3 pt. With LokSound decoders, after doing the BEMF auto calibration, the linear speed table tends to be spot on. If you really want to use the three point curve, and you want linear response, just set CV6 = (CV2+CV5)/2
The real key on ESU decoders is to always always do the CV54 auto cal prior to any speed matching.
