The NAUA is at the beginning stage of evolution and states that their hopes are to continue to expand further as a service organization for all Liberal Religion. https://naunitarians.org/
The NAUA is not a denomination.
The NAUA indicates that members can be both members of the UUA and of the NAUA.
Membership can include Individuals as well as whole Congregations.
All are welcome to NAUA
"We welcome all people committed to liberal religion and embrace the principles of freedom, reason, and tolerance in pursuit of their individual paths. You do not need to be a Unitarian or a Universalist to join."
As the NAUA is not a denomination, and whose sole purpose is to rattle off all the perceived failures of the UUA, I'm not sure why discussion of NAUA is housed in this forum.