When using Centramatics, they refer to it as "Pre-Balancing", they say its not required, but its not explicitly recomended against; downside is likley just adding to more un-sprung weight.
Centramatic is an industry leader in wheel balancing technology!
www.centramatic.com
In most cases, pre-balancing is not required. However, if a vibration still exits after installation, a computer balance of the problem position can indicate a mis-mounted or defective tire, a bent wheel or other "out of round" condition, which balancing alone cannot correct. Wheel bearings should also be checked and defective parts replaced.
EDIT: I'm not an expert on them by any means, just have done a lot of research and reviewing what I belive are
actual independant reviews.