All balancing methods give varying levels of ease and success... Nothing beats pulling the wheels and doing the balance without the rest of the machine getting in the way... While the wheels are off, drill the webs for counterweight balance installation on crank throw radius and you are well set for having a really smooth engine later.... This does of course rely on the gib keys being able to be pulled, but well worth the effort...
I was reminded of that today when i ran up TM2 .... From 0 to 700 rpm there is one very narrow rev band, around 300rpm or so, that causes a very small sway in the genhead as the chassis harmonics match..... Absolutely smooth for the rest... And the whole gamut is not bolted to terra firma even....