Frontend Submissions - Vendor Shop Pages
With Frontend Submissions, each Vendor has their own Shop page, which is an archive of their products. The parent Vendor page is a normal WordPress Page with the [downloads] shortcode on it. You can choose what page that is in Downloads → Settings → FES → Forms/Pages.
Assuming your Vendor Page has a slug of "vendor", then you can append the username of any vendor to the URL to get that vendor's personal Shop page.
In the above example, Topher is a Vendor, and his username is topher. Then the front end will look like this:
The [downloads] shortcode is smart enough to know whether to render the products for all vendors, or only for the one you're looking for.