Sometimes a salvage item will be scanned into sort twice, I'm able to void with defective salvage because it has an LP. missed salvage only prints a white label. Is there any way to void one of those items out of the box?
You mean the missed salvage item was accidently scanned twice?
If the white label has a process number (much like the lic plate on defectives), you could - in theory - attempt to key it in lieu of a lic plate number while in the "void LP" screen.