Cabinet guy wants me to do this so a machine can bore the holes and also not ruin the finishes. Is this normal? Seems hard if I can't hold knobs up to the pieces.
Depends. I asked for them to not install our hardware (and to not charge us for it... that was during the contract part.) I wanted hardware they didn't have, and I wanted to make sure they were installed exactly where I wanted. DH drilled and installed. Our finish wasn't ruined.... Any little imperfections in the drilling would be covered by the hardware, anyway.
It sounds like you've already paid for them to install hardware....... so either eat that cost and install yourself after..... or get really good at imagining!
Can you go to the shop and try different knobs? Or at least see where you want them placed so they can drill and you just add the knobs once installed.
I will be at the shop, but the sample hardware is on a display unit so I'm not sure I can actually take knobs or pulls off.