Suspect classic pilot jet zinc oxide crust and also a failure of the ignition timing to retard with lowered engine rpm OR like I had do this on Peel once, the dang carb bolts got loose and would suck air in unless I held throttle open enough to suck the carb close to seal extra air out. It took me a while to find this by accident in shed just looking around to finally see no bolt and carb gasket hanging out a bit.

OH yeah had this another few times on Ms Peel that turned out she needed some level of hi engine vibration to keep enough connection going in broken smoke conductors, which also took me a while to figure out. Some times it was obvious in line with ignition wires by others was brake light wires grounding-shorting out, found only because the rough ground crossings bounced engine stalling with the bumps more than throttle relaxation.

After a decade or so getting Commando to work consistently you are qualified to advise NASA on its troubles.

One thing a Commandoneer needs, ugh, among many other spares, is a hand full of fresh spark plugs and knowledge that they come bad right out the box, which I never ever in my life experienced but on Nortons, though I suspect its Brit Iron wide phenomena.

If not carb and not Pazion ignition then the fun begins to hunt for other things in combos till ya prove your manhood to be worthy of a road going Commando. Times like yours I so wished to be a baby and pay someone to take care of me, but alas not enough money nor experts around so stiff upper lip and begin complete inspection and dissections of everything you know can't be wrong. A voltmeter would help to see if gaps in the voltage along with the misfires or stalling. I have fixed or found some things by juvinile swift smacks and hard kicks, much to my peace of mind but lingering poor self image, eased by working lights and smooth running riding.

UGH - it can work both ways, creating another fault but at least the satisfaction of knowing the cause and location of the new one.