As a snake/close range varmint gun, it is passable but would be better with a slow twist barrel.
As a means to dispatch a venomous snake when absolutely necessary, and at such a distance as would offer no option to let it move on, the pattern with #7 1/2 shot out of the 2 1/2" barrel of my PD Poly is completely dense enough. 10' or less, otherwise if not in a yard, or place where it might be a threat to children, it can slither on it's own way.
Maybe the faster twist of your theory has creedence with a longer tube, but it has not proven to be the case with a 2 1/2" barrel.
As for accuracy with 45 Colt, my short barreled Judge does as good as I can, and as good as any other snubbie I have shot. Actually, better than some with holding a 2 1/2-3", 5 shot group, off hand @ 10 yards. Perfect center mass hits as well.
With Federal Handgun 410 000 buckshot loads the "pattern" @ 10 yards looks very similar to the "group" shot with 45 Colt.
Now, to my thinking why my PD Poly is kept alongside the seat of my truck as car jacker defense. The first three rounds up are the Federal 000 buck. Ballistic gel tests have shown this round drives four .355 diameter projectiles to, and past the 12" FBI standard. With one pull of the trigger that is four chances of hitting the spine resulting in an instant stop. Two more rounds tor a total of 12 9MM/380 holes.
One interesting test I would like to see, but haven't found would be pattern with 000 buck at very close range. I'll just have to do that one my self, easy enough next range trip. Thinking car jacker at my door distance of two or three feet. My thinking is that the shot will stay very close together at that distance. Say an inch, maybe a bit more, or less. That would be one massive wound, and I don't care how high, or pumped up an assailant is, that's going to stop him!
Now, for the final two rounds. Backup in case there is another threat at a longer distance.
The PD Poly is not my EDC, nor what I consider my main SD handgun. Just a specific firearm for a specific purpose in SD that doubles as snake insurance in the berry patch. With the bonus of being lots of fun to blow stuff up with!
But that's just me. An inexperienced 70 year old that has shot almost his entire life. But has never written a book, hosted a TV show, or trained Mall Ninjas.