Yes you can service MDM without having the enterprise account but you cannot Vendor it. This is the description of it
The Mobile Device Management (MDM) protocol provides a way for system administrators to send device management commands to managed iPhone, iPad, and iPod Touch devices running iOS 4 and later. Through the MDM service, an IT administrator can inspect, install, or remove profiles; remove passcodes; and begin secure erase on a managed device. MDM uses the Apple Push Notification Service (APNs) to deliver a "wake up" message to a managed device.
The MDM CSR Signing Certificate provides a way for MDM vendors enrolled in the iOS Enterprise Developer Program to sign APNs SSL certificate signing requests (CSRs) for their customers. The signed CSRs can then be submitted by the customers to Apple for APNs SSL certificate issuance. Review the Mobile Device Management Protocol Referencefor more information.
This message is only inside an ios enterprise account -> certificate -> other tab