I recall Roger Barlow doing an article on the cube & disc shot some years back, I think was in an old Gun digest. I have never shot either of these myself.
Spreaders are most often considered impracticable beyond around 25 yds. I tried to never shoot real close to any dog on a hunt even without spreaders. It would take an extremely variant pellet to hit a dog if you are using good shooting practice in my opinion.
I "Almost" shot a good beagle once on a rabbit hunt, but that's not really connected to this thread. Just a case of a dog being where I didn't know she was & as I pulled down on the rabbit she suddenly sprang out of some cover right in front of it. The rabbit was running toward me just outside the cover & I had already sent the impulse to pull the trigger. I wasn't able to stop my pull but did manage to rear back & throw the shot high, was shooting a 12 gauge cylinder bore muzzle loader.
