The box finish is 500/500/500 Abralon/1500 Abranet Soft/Factory Polish.
To smooth it out, you may want to try 500/4000 without polish. That will give the ball additional surface which will cause it to read the mids earlier and get into a heavy roll sooner. Usually this type of surface can help blend out the conditions causing over/under.
If 500/4000 doesn't work, then you can go 500/3000 or 500/2000 as alternatives.