Any chance you're using an A H engine ? That would explain it...
Much smoke screening there in that explanation... Maybe a little CYA too....
Only current engines I can think of with forged one piece cranks are the not so current Twin Star and the Limbach 275...One piece cranks require rods with caps...Roller bearings for rods with caps are more $$$, rods have to be perfect, perfection is expensive, follow the money