Multi - Tenancy is an architectural pattern in which the applications are built. The Business Edition provides Automation solutions for Subscription Management, Customer Management, Recurring Billing, Invoicing, Metering etc which comes as a stand-alone application which will be integrated with your SaaS based business Solution with minimal integration and hence your business application could have been built on any technologies.
Multi-Tenancy is an engineering feature of Cello hence applications that would like to be built as multi-tenant or migrate from single instance model to Multi Tenant Model have to follow the Multi-Tenant Architecture of TechCello that comes only with Ultimate Edition. TechCello provides suits of Non Functional Components which are common across all sorts of SaaS applications irrespective of the Domain/Business they are in. In order to take full advantage of the features and modules, it is recommended to follow the Architectural Pattern that TechCello Propose Which also aligns with Microsoft's Multi Tenant Architecture.