You just want to get into a philosophical discussion of right and wrong, don't you. Were you captain of the high school debating team? OK, let me make my position clear. Firstly, half measures are not right for me. Secondly, deciding what's right is ultimately up to the individual.
No, using factory ammuntion cannot be classified under what's "right", but what is best under the circumstances. Further, it does not compromise my rule of no half measures. I made black powder, when I was a kid, but would I now make it and load it into a muzzleloader? No, not under the current circumstances, where I have and abundance of powders to choose from. Making black powder, and slug loads from trap loads might be something good to know if circumstances were ever to change, but for the time being, I'll do what's best.
I just think it is ironic that you speak about making slug ammunition the "right" way, but end up using factory ammo.
Without experimentation, nobody would be shooting a gun today. People have been stuffing all sorts of things in shotshells for along time. Using the same weight slug as shot, this experiment is relatively benign, I think.