Modern Vespa

I searched NSM for "cold start" and scanned/read through 7 pages of results, but didn't find something quite like what I'm experiencing.

When cold starting, I pull the choke out, no throttle; bike starts on third kick just about every time, but then stalls within seconds.
After starting/revving I push choke back in and hear the revs come up a bit (as expected) but bike stalls when I let off throttle
After each stall, it starts again on next 1-2 kicks.
Occasionally when this happens, the throttle is also bogging when I rev it.

This morning I held the throttle steady and it was all over the place, then I revved higher for a bit and the issue went away. This happens every so often.

After a few starts and some revving, the issue seems to clear up, idle is fine, and I go on my way and no stalling at all. Acceleration is smooth, performance as expected.

Recent work done:
Adjusted timing with strobe and degree wheel
Stator was re-wired last year
Tightened carb mounting bolts; examined and cleaned all jets, float, needle, banjo connector & washers.
Checked for air leaks around carb box and found none.
Adjusted idle and mix screw - both are close to "normal settings"
Verified fuel flow to carb with/without gas cap closed

Stock motor, BGM Big Box exhaust, 24/24E Dellorto carburetor

I live at/near sea level.
Jetting:
Starter: 60
Slow running: 50-120
Main: 122
AC: 120
Mixer: BE4

Ideas? Suggestions?

FWIW, I had almost the same situation last month and it turned out to be the CDI.

I was wondering about that, as a co-worker with some 2-stroke experience was troubleshooting with me the other day, and he thinks we eliminated fuel as the problem, so was leaning towards fire as the problem.

I was under the impression that if the CDI goes bad, it just stops working (happened to me on my previous P200E years ago - would not start at all and had to replace).

But I'll consider it. I have a spare, though I don't know if it's any better than what I have installed now. I'll try swapping and see if it helps. Thanks