I am also seeking expert troubleshooting guidance on a similar problem I'm having with a 2004 Ford Crown Vic.

My vehicle has low mileage (76K) and it mirror the same problem you're having but has progressed to acceleration/deceleration stall after normal engine warm-up.  After about a minute; sometimes less,   the vehicle will start up and I make it home ( I no longer drive more than two miles with this car due to this problem ).

I performed the same maintenance you've done in addition to changing the ECM and IAC for shits and grin even though my IAC PID read normal.  I changed the ECM ( I meant PCM ) because when I was monitoring the network SCP protocol Pin 10 at the DLC using a breakout box and a lab scope I would lose 5 volts SCP-, Pin 2 (SCP+) was still active.  Didn't fix the problem.  At the time of stall, I am still able to communicate with PCM.  DTC scan yield NO CODES whatsoever. No network U codes. Afterwards, a test of all network modules pass with no DTCs.

Car has new fuel pump and rail pressure monitored during test drive remain in specs.  Fuel trim (LT & ST) in specs at 15, 30, and 50 MPH.  CKP reading varies with RPM changes and no glitches captured on scanner recorder.

EGR tested KOER and engine will stumble as dwell percentage is increased.  Keep in mind that this EGR module incorporates the MAP sensor and readings in specs at 15. 30. and 50 MPH.

So what is preventing TID 56 Misfire Monitor fail to completed.  MY CKP scanner readings change during test drive and engine rpm will increase and decrease when tested stationary.  Engine does not misfire and mode 6 data for all 8 cylinders read zero ( 0 ) misfires.

Also has a brand new battery, completes OBDII Readiness, and passes CA smog check with flying colors.  I'm at wits' end - HELP.

Hopefully, my stated problem will shed some light on our problem to help both of us resolve this complex issue.  Someone. please help us take on this challenge.  Thanks 

Taotaomona