Have you tried managing the data with Tableau Prep? it might be easier to maintain the data using that tool and with the new scheduling enhancements this might be the better tool. Your Creator license gives you access to Prep directly so you might try it.
I hope this helps
Hey Patrick, So sad sorry, our company doesn't allow us to download Tableau Prep, otherwise I would have tried and played around with things in there.
I did find a funny glitch in Tableau that by doing this fixed the issue.
Initially i wasn't able to add new items to the pivot that where duplicates because of uppercase or lowercase. So i couldn't unpivot and pivot everything again to existing pivot.
My solution was to update the column headers, click on worksheet in datasource the carrot symbol (drop down arrow) select generate names automatic then switch it back to field name first row. This solution and weird glitch switched the upper and lower case items all to uppercase.
Thanks for circling out and providing feedback