Where items have two dimensions - e.g. foot size/calf width - these are currently being sorted by Dimension 2, but still displaying by D1, D2 in the dropdown. For example, these boots are displayed with a sort order based on calf size but listed as Foot Size, Calf Size for each individual item.

This is confusing for customers, who would rather find their foot size in the list and then see the calf size options. It makes the dropdown look confusing and messy. How can we choose which dimension controls the sort order? Swapping the dimensions round wouldn't work as this would change the order they are displayed in for each item. This should either be something we choose or automatically set to use A1, as this is the primary dimension.