Yes, that does seem to be a limiting factor. It is odd they don't have an "Always Relist" as one of the checkable boxes on the right.

If you do check the "At least X items are available in Inventory", that method seems to be workable. Relist and Inventory is working for a few that have posted success with that combined method. I know that's a little more work, but it does present a method.
Danno