Hi Richard,
I've actually made some progress myself too, just for fun I'm attaching a photo of my little testbed. It was designed a long time ago, at the time I was Little "afraid" of the PCPWM module so it's actually using the normal CCP module for the PWM output, 19.531kHz, 10bit resolution. What PWM frequency are you using to get 14bit with the PCPWM module?

Name: Testbed.jpg Views: 1241 Size: 237.4 KB

Anyway, my code seems to work pretty good in the real world too. PID-rate is 1220Hz (derived from the PWM time base, 1:16 postscale). Initially I tried to run the profile generator "slower" than the PID but it really didn't want to fly properly. Now it's updating at the same rate as the PID and it's working pretty good. The CPU load is pretty high during deceleration but I'm "only" running it at 20MHz on this board so at 40MHz it'll be more relaxed. Acceleration, velocity and distance can be set arbitrarily.

Time is limited and motivation to work on it comes and go but I'll keep poking at it.

/Henrik.