IG 17" steel wheel vent holes

[JackieTreehorn]

More than slightly OCD observation.
Has anyone else noticed that 3 vent consecutive holes on the 17" steel wheel are slightly smaller diameter than the rest?
That's "on purpose" correct?

 

[JackieTreehorn]

Manufacturing oversight?
Die punch replacements were incorrect size that shift?

 

[PilotMike]

Look again and you can see the 3 holes are opposite the valve stem and TPMS. Its for balancing.

 

[JackieTreehorn]

That makes sense.