No, Pat. RC is still at FET gate, just FET drain via C to Q1 base. Value of C could alter the severity of the FET's effect, but would still not have much effect on overall action. If connecting C to Q2 or Q3 base likewise, though I'd be cautious of messing up Zout of Xtal filter. I'd be trying around 100pF there, same as the coupling cap.
