A couple things, now that the dust has settled.....
I learned the technique very young, in a goose bliind with my father. It was the fastest way to charge the shotgun. Letting a cripple get away was not allowed.
Later, in the Correctional system, it was taught as the fastest way to get one shot off.
Prison riots are "Target Rich Environments". One at The MD House Of Correction in 1971 saw about 30 inmates shot off the yard fence during a "Major Disturbance" there by one officer. He had an M-1 carbine and a Model 12. When everything was over he had one round of 30 Carbine ammo left. No inmates died, he held his shots low. Working at MHC, we expected to have to repeat the experience. Eventually we did in 1981 but no firearms used in that one.
The premise was that a weapon shot empty MUST be recharged ASAP. Through the EJ was the fastest way to get one shot ready, and a good hand could make a fair rate of fire charging and shooting one at a time.
Of course, if we didn't need that shot instantly, we turned the weapon over and filled the magazine with four more buck loads.
As to whether anyone here should do it, it's up to you. While a bit more complicated to learn, it IS faster to get ONE round ready.
Also, the technique was incorporated into the qualification COF. 4 rounds were in the shotgun and once empty the 5th was inserted in the EJ, cycled and fired. Most folks has little trouble with the technique.