Choke is a performance, not a constriction. We do need choke, but we may not need as much constriction as in the days before shotcups.
I ran some 12 ga 1 1/16 oz B&Ps through a cyl M-21 barrel on paper. They gave something between IC and LM patterns. Not shabby. This helped me understand why I did reasonably well for many years using cyl and good factory traploads.
Payload matters. Alot. What one can do with a good B&P 1.25 oz load through that 12 with .000 is one thing. Trying to find a use for a 1/2 oz .410, or 3/4 oz 28, through .000 is another. How useless? Well, at 20 yds you will not reliably break a centered clay with the .410 and #9s. Nor will you reliably tag a centered grouse or WC with the 28 and US #8s. Sometimes you will, sometimes you won't.
Then, I haven't tried B&Ps through my .000 28.
IIRC, MM was discussing subgauge light loads and 50 yd targets. I know you can groove a repetitive long target and hit with a tiny effective pattern. But I don't understand the point of such an exercise, as you would never deliberately do this in competition. Nor would one possessing ethics do so in the field.
Sam