Hi @cooper_david_a
This is not currently possible. But Every customer request that we get, from meetings, emails, forum posts etc. gets collected and categorised in our feature request database. This information is used to prioritise the features that we build. I've added your request to our database.
A possible workaround, that will move with the balloon, is to use a customer revision scheme, and to tag the balloons with a revision marker. The drawback, is that the quantities will be in triangles, and will be static.

Set up a custom Rev scheme in Document settings

Then create a revision table with the values for quantity as the revisions. Note that you can delete the table once this is set up so that it does not show up on the sheet.
