Another UOM Conversion Change question

[littleboy]

I think this is a different situation than I've seen in other posts. We have a UOM conversion from CS to POUND (i.e. 1 case = 30 pounds), and at some point may want to change it so that 1 case = 28 pounds. In our situation, all transactions are done at the CS (primary UOM) and the weight is only used in calculations to print on shipping documents. Is there any harm in just changing the 30 to 28 when that time comes? Again, there are no transactions that reference the weight, no PO's, no SO's, no financials, etc.

Thanks for your insights!
Bill