Can my multisite hosted at WPMU provide databases for sub-sites?

– A user joins and upgrades to a paid membership which allows members to set up ecommerce sites. These sites would consume storage forcing me to eventually move the sub-site to its own hosting platform and out of my community platform. Although I’m aware of this outcome I wonder if it’s possible to have new databases, which are essentially new hosting setup under a WordPress multisite install? I use Paid Membership Pro to handle memberships and control the allocation of sub-sites to include the number of credits (websites) assigned to an account.

So basically you join and instead of you consuming my storage you’re set up on a bronze membership with the option to add additional storage (upgrade) as needed.

Any responses appreciated