I would love to be able to send my client to a marketplace of Webflow templates that is white labelled, so they don't have all of the Webflow specific stuff, and it resides at a custom domain.

At the minimum level to be helpful all it would need to be is a feed of the available templates, some screenshots and the price.

Getting a bit more advanced, if it had the 'Preview' option, but not the 'Preview in Designers' option, that would be fantastic.