Yes, I have heard of such things. Damn thing would be uncontrollable and illegal at the same time.
It would only be illegal if it was designed specifically for shotshells. If it was designed specifically for 45LC, but that somehow or another it could be made to fuctions also with, ahem, .410 shotshells, well, that wouldn't be illegal. (I think)
There are already 2 barrel .45 derringers out there that will take 410 shotshells.