I thought I had seen where the version after the Nano V2 was released was going to be 6GHz and they plan to still keep the cost down.
The one you linked appears it could be a 2-port system but I could not find any details about it.
Maybe this is talking about it? I don't have an account and can't seem to view it.
https://www.eevblog.com/forum/rf-microwave/chinese-vna-up-to-6ghz/