Modifying pop-up menus in Numbers
I have a column that uses pop-up menu for data input. As the spreadsheet becomes more complex I often have reasons to change/update the options in the pop-up. But I can find no way to paste the new pop-up as a "style" over existing data. The paste adds the new pop-up items, but also changes the contents of the cell. I'm not Nostradamus--I can't guess all the possible pop-up items I'll ever need before I start entering data.
How do I update pop-up selections without losing my existing data? I don't need data updated to match the new options, I just want the options to change.
And, as a follow-up question for Apple, if this ability isn't built in yet, why?!
Mac Pro, macOS 10.15