In case anyone is interested: a former colleague of mine (who knows Lawson front/back end better than anyone I know) has developed a program in the past that would allow anyone the ability to add any fields they wanted to delivery tickets/labels. If you are interested, I could probably arrange a call to connect you with him. Doubt it would be a free service, but assuming the end users (and yourselves) aren't desperate for such an enhancement
For par location labels We use Zebra Designer Pro 2 and use an Excel spreadsheet as the database, updated using Addins as needed.