pinning the tubes/lugs was something Pelizzoli was known to have done when he (and/or assistants) were building CIOCC frames.
I'm not 100% sure but I think that the Bonati factory did not pin: their operation was far more automated and volume/output was much higher, still a fair number of build operations were done by hand, but they had a lot more machinery and jigs.

If you run across the video with the (in)famous pop-classical soundtrack (shudder!) this vid showed their factory hard at work making Ciocc, Conti and John frames from automated tube cutting to paint and fully built bicycles packed into vans for delivery...but I'd reco you turn the sound "OFF"!