I know how manufacturing works in the real world.
That is why I am spending money buying machining work.
And real machinists make the parts per the print.
You are a self-proclaimed incompetent boob.
If you changed/modified any customer parts as you chose (outside print specifications), you would not get paid due to the 100% rejection rate. Paying customers would stop coming to your shop (hmm, is this your real life ???).
And that would put any place you worked out of business....