Hello Benny !

No, for now, it's impossible - everyone in UNA manages his own Snipcart. But in v12 will be introduced the Single Seller mode for inner payments. The users will have the possibility to sell things to one payment account and later the site's owner will share the sum with each other.

Does this mean same thing as Multi Vendor? Any hope of having a module that supports M V?

One store, multiple sellers. Ideal for community market