One situation, I bought a used Hunter GSP9700 Roadforce balancer and used it on a 21" Rim setup running low profile tires. The wheel was a stock setup from the factory (Mounted and balanced from factory). When driving at freeway speeds (approx 65-75) there will be periodic vibrations with the vehicle. I thought it may be the road. I drove on different lanes and different freeways (asphalt and concrete). Threw the tire on the balancer, no problems... The wheel was balanced. I enabled the roadforce on the machine, and it complained that the Roadforce variations were high for one of the wheels (approx 26 lbs). After match mounting the tire to the wheel, it reduced it down to 12 lbs. I match mounted the remaining wheels and and re-balanced. I test drove the vehicle again. The vibrations were gone. I personally believe it makes it difference, but more prevalent with larger rims with lower profile tires. Trucks/SUV have more tolerance than sedans than sport cars. If possible, I try to reduce the roadforce variation to under 15 lbs. The machine has a maximum setting of 26 lbs, but I think it is more for sedans. Trucks/Suv are higher.
Just my .02.