This message is just to close out this discussion in case someone is searching in the future.

I was not able to implement any of the proposed ideas using the CCP module. The project hardware is stuck with the 16F690. The CCP1 and CCP2 pins are already committed to other functions. The proposed ideas sound good, so I'll try them in the future upon redesign.

I measured the interrupt service routine of the present elapsed timer using the stopwatch function in MPASM. With a 16 mhz osc the ISR is only 2.5 usec. I don't think this is enough to account for the servo jitter, so the jitter must be coming from somewhere else.

I've ditched the elapsed timer and gone to servo frame cycle counting to keep track of time. That's working okay.