Dezi::MultiTenant has been released to CPAN.
From the documentation:
Dezi::MultiTenant provides a simple way to mount multiple Dezi::Server applications in a single Plack app using a single configuration structure.
Dezi::Server allows you to serve multiple indexes, but all the indexes must have identical schemas.
Dezi::MultiTenant allows you to server multiple indexes per server, and each server can have a different schema, as well as individual administration, logging, unique configuration, etc.