Hello, @jonahwills,
The theme for the marketplace application will be used for personal shops accessible via subdomains or custom domain names, such as https://fmapp.download/. This usage scenario involves individual shops that may have their own unique URLs but are still part of the overarching marketplace platform, so you can use the MultiVendor plugin for this purpose, and come with the theme package.
Porto WordPress is fully compatible with Dokan and WCFM plugins and both are pre-packaged with the theme so you can use any one that better suits your requirements.
Further, To determine the appropriate licensing model on Envato ThemeForest for this specific usage scenario, consider the following points:
Regular License: Typically, a regular license allows the theme to be used for one single end product which end users are not charged to access.
Extended License: This license allows the theme to be used for one single end product where end users can be charged to access or use the theme.
If each subdomain or custom domain is considered a unique installation of the theme, you may need a separate license for each installation.
Further, you can contact Envato and ask more questions related to the license usage concern, they will guide you properly.
Best Regards,
PThemes Team.