This improves lag from smartshops a lot, as I was able to see first-hand on Tunnelers' Abyss, and the api just ends up being much smarter than the original. The new currency system works great, allowing you to make purchases such as buying something that costs a "10 note" for two "5 notes". Additionally, the smartshop updates with the meta from the item which will be sold to you; in the original, this was not implemented and could be used to sell you a below average item while advertising a fully-upgraded item.
Fair warning, your smartshops will mostly have 2D sprite displays now instead of the 3D model entities. This can be a painful reality, and some people were fairly upset about it, but in the long run, your client will thank you for not having to render those 3D entities.
@CalebJ the aesthetic interests of players is actually something i think is very important. while i think the current menagerie of shop entities is optimal for FPS for low-power clients (almost, i have a couple more ideas for minor improvements), i think i should add a setting to allow people to either
optimize for FPS (current default)
show 4 wielditems (old behavior)
only show wielditems or upright sprites (a compromise which is less visually jarring)