Current state of the popping - car is going into the shop next Tuesday.
https://youtube.com/shorts/j-48WRmYdPU?feature=share
If you listen carefully you can hear the very slight pop over the wind noise. This is decelerating from 2k down while in gear. Also - randomly will still do it at idle.
Outside of this the car is still running better than it ever has. Every now and again while at speed and not accelerating I can feel what seems like a minor miss / stumble and it also needs just a tiny bit of gas on cold start. Will be interesting to learn if this is still possibly tied to a leak on one of the intake runners - or something else.
Will report back on what the shop finds. Let me know if anything else comes to mind to check from the community.