Intermittant 2012 Kia Forte P0304 on cold start

I am a Dealer Tech in Canada working on a 2012 Kia Forte 2.0L with a intermittent P0304. Vehicle has been to me twice with the CEL on for P0304 in history and came from another shop. First, I simply switched #4 coil and plug with #1. Vehicle returned with same code days later P0304 history. Freeze frame shows misfire occurs at cold start. Next due to lack of time, a quick injector swap from cylinder #4 to #1 and found software update for cold start logic. Again days later vehicle has now returned and vehicle is currently in my possession until fixed. Problem I have is that I cannot duplicate the misfire. In the meantime, I have checked coil power and control, injector power and control. (although pointless since not misfiring). Performed cam crank correlation waveform. Vehicle only has crank sensor and intake cam sensor. Sync marks line up with known good from dealer troubleshooter. During a coal soak, I pulled cylinder #4 plug and bore scoped for coolant leakage into cylinder, none found, but when started, vehicle still did not misfire. Google searching, I have found an US service action pertaining to this symptom, but service action is simply a software update for cold start cylinder 4 misfire to the VCM (Variable Charge Motor), used to swirl intake air flow during cold start to reduce emissions. This service action pertains to a 2010 forte and in Canada, this information does not exist. However, I did find a cold start logic update and performed it with no change. Our dealer Tech line is just as useful as the factory flow charts. I am now suspicious of a vacuum leak at cyl #4 or a problem with the VCM, but cannot duplicate misfire.
Anyone ever come across this problem? Suggestions on recreating this misfire? Thanks in advance!

the cold start misfire is screaming an intake gasket leak. it will leak when cold then seals up when it gets warm. id smoke it cold. I had a Hyundai that had that problem last week customer "diagnosed" it as plugs and wires. I installed them still misfired when cold. then they paid for a diag and that's what I found

I like cheryl's suggestion to smoke the intake cold. Alternately, you could leave it outside overnight, and be reading in the morning with a water bottle to soak down the intake gasket surface when you first start it up.

Any possibility of carbon fouling on the intake valves? I know this isn't a GDI, but it's still a potential problem. Not sure what you have available for doing upper end cleaning, but it may be worth a try.

This morning, I was again ready with carb clean, but start it up and no misfire temp outside is 6C which was an ok temp based on the freeze frame data collected. Cannot duplicate the problem still.
Freeze frame:
Fuel Trim Bank 1 Long Term = 5.469%
Intake Manifold Pressure = 7.397psi
Engine RPM = 1603 rpm <-- off idle turns me from vacuum leak though
Speed (OBD) = 0 km/h
Timing Advance = -6.5 degrees
Intake Air Temp = 15 degrees celcius
Throttle Position (Manifold) = 14.9%
Run Time Since engine start = 8s
Fuel Level (From Engine ECU) = 47.84%
Barometric Pressure (from vehicle) = 14.504psi
Voltage (Control Module) = 14.58v
Engine Load (Absolute) = 38.431%
Commanded Equivalance Ratio (Lambda) = 1.021
Relative Throttle Position = 7.059%
Accelerator Pedal Position D = 15.294%
Accelerator Pedal Position E = 15.294%

Performed relative compression test. Looks ok.
Throttle body has been cleaned.

Relative compression is cyl 4 triggerd from coil

Cam / Crank pic didnt upload correctly previously.

Finally, the car acted up for me. I was monitoring the VCM(Variable Charge Motor) with my Hantek1008c scope during the cold start. Motor position voltage went to 4v and did not see motor control to make motor move to this positon. During normal idle operation, motor position voltage stays at approximately 1v. Will need to see this happen again without misfire on cold start to see vcm position value. VCM position stayed 4v after fast idle dropped and misfire disappeared. The vcm position did not change until I snapped the throttle. Unsure on when this vcm position was commanded to switch but I never saw it unless it happens when the car is off when ECT, IAT and Ambient temp reach near same temperatures. After fast idle dropped or sometime thereafter vcm control was taking place, but the position voltage was not changing. I am now very focused on this VCM, but would like to capture more data, Unfortunately, it will only control it for a cold start scenario for lower emissions. I must now wait till later for my next cold start event. Will try my best with my piece of crap scope to capture and save this data.

Today I gained access to a smoke machine and smoked the intake with it cold. No leaks found, miraculously it sealed up to drop the flow rate on the smoke machine. Is it even possible to have two enough valves closed to seal the intake from the exhaust.... Tried also spraying the intake during cold start with water, nothing found. Borescoped the injector opening to check for carbon on intake valves, none found. Removed cylinder 4 plug and pressure tested coolant while cold, no leakage of coolant to cylinder found. Swapped VCM (variable charge motor) from known good car, didn't fix. Side note, I don't understand the VCM control voltage data collected, as it appears it tries to command the motor to move, but the position voltage stays at 4v on cold start until throttle is touched, then drops to 1v. Then, PCM goes to duty cycle motor control wires on and off at exact same time, which would cause no motor movement. Only during the cold start period, I see just one control wire cylce in what looks like an attempt to move the motor... scope capture attached.(yellow and blue trace are motor control, purple in position voltage)
Wish I had in-cylinder pressure transducer to play with. Question...do you think a valve sealing problem would be evident on vacuum gauge during cold start misfire and normal non misfire condition? Haven't checked yet. I know I am over complicating this, but man its really killing me.