The industry standard after balance limit is 0.15 IPS, this where your average balance shop will say it's "good enough".
Vibration Range Limits
DANGER — 1.25 Inches Per Second (IPS) Peak Amplitude. The propeller should be removed and a static balance performed.
VERY ROUGH — 1.00 Inches Per Second (IPS) Peak Amplitude. Propeller can be dynamically balanced; however a large amount of weight will be required. A propeller static balance is recommended. Operation at this vibration level could cause damage.
ROUGH --- 0.50 Inches Per Second (IPS) Peak Amplitude. Propeller definitely requires dynamic balance. Long term operation at this vibration level could cause excessive wear.
SLIGHTLY ROUGH -- 0.25 Inches Per Second (IPS) Peak Amplitude. Dynamic balance will improve passenger comfort.
FAIR---- 0.15 Inches Per Second (IPS) Peak Amplitude. This is the maximum acceptable vibration level after dynamic balancing.
GOOD ---- 0.07 Inches Per Second (IPS) Peak Amplitude. Vibration levels below 0.07 will not be detectable by pilots or passengers.
Источник:
https://www.expaircraft.com/PropBalance.htm