So on the topic of wild, off the fucking wall merch ideas... there are a couple of sex doll manufacturers that make anime-styled sex dolls and will do custom faces and hair for them. There are already a number of vtuber dolls they've made before -- pic related is a Gura doll they produced and have on their site as an example of what they can do.
What are the odds of an official VAllure collab with a company like this? Would you buy an official, actually licensed sex doll of your oshi? Even if it costs ~$1500+?
Link for examples -- this site is just a vendor, Aotume is the actual manufacturer, but they explain it in English.
https://www.myrobotdoll.com/collections/aotume-anime-dolls 