The wiki article (at least right now) uses both Cadence and Cadance. Also, her full title is Princess Mi Amore (excuse the lack of emphasis mark) Cadenza, so why did her name change to include an 'a?' Oh well. I think it's more of a preference on her name rather than canonization. I'm not complaining, just arguing
Now about the art! I'm liking all of these wallpapers you make, and grabbing them all. I like how minimalistic they are.