Sorted myself out! Thanks anyway!
For some odd reason, this came up 4 or 5 times this week! I put together a simple example app that demonstrates sorting a popdown or stacked list in the non-default manner: https://www.appsheet.com/samples/Built-from-your-app-spec-?appGuidString=22fbb421-d3e8-4d05-831a-b6247def3676
Hope this helps for anyone else running into this item.