You know, I was going to stay out of this but you keep dragging it up. So I'll help you out. I worked in production engine rebuilding shops. They make money three ways. They by parts in bulk and get a big break. They cut corners, especially on **** like balancing, finish honing, setting clearances and accurate machining. Third, they blow you up on the warranty.
So I'm not talking out of my ***. I'm TELLING you from experience. They can't do it any cheaper than any one else except by what I posted. I'd bet everything I have that your balance job is at least, AT LEAST 10-15 grams off. Will you know it? No. But I would have. I'd catch it on the balancer and I'd make it under 5 grams for a street car. That's how they make their money.
Oh yeah, they pay like ****, most people that work there aren't machinists and only do what they are told and have no idea why they do or don't do something. They don't know if it's right or wrong or what it should be.
So there you have it. From EXPERIENCE. You may get lucky. You may not.
BTW, bet they didn't use a torque plate on it either.