No, we never make changes to the core files of Magento. We always follow the best guidelines which have been governed by the Magento. Magento Multi-Vendor marketplace module is coded on top of “Magento MVC and ORM system” and follows the standard way of Magento Application Programming. Marketplace Module is as scalable as your Magento does, which means it will not affect your existing store performance and will support all your standard Magento cache handlers.
Please do contact us for any further queries or requirements.