On Save groovy looping for every line item in sales order each time it is saved

Summary:

Customer raises sales orders containing large number of items. Each time the sales order is saved the On Save extension is triggered and performs the same validations across each line even though there has been no change. This is leading to performance issue when many lines exist.

Customer only wants On Save to validate new lines or those being updated.

Same for when a sales order is being revised.

I am curious to know if isAttributeChanged() is useful in this instance

Any suggestions will be great