Custom Item Voucher/Aurora Toolset Question:

What, if anything, does the "Masterwork" quality do for an item?

For voucher items, I think they're just for descriptive quality.

There are base "masterwork" items in game, but those are for crafting, and I suspect have a specific tag, so there's not a chance you could mistakenly turn your 'master work' voucher weapon into something else with the crafting system

Exactly. For now, there is nothing but flavor that goes with that quality.

I gots a question

When I first started on the server, I remember that a speed increase ala boots of striding and springing could be added to custom items. The current list of "Aenean special properties" doesn't list that anymore. Is it still possible to get that effect with a custom item?

It could be, if you ask nicely. It was never listed, you had just asked me about it and I said yes, for an undetermined price.