Is there a reason why you don't want it to be under the openstack namespace?
The only reason that comes to my mind is not technical at all.
I (not saying we, since we haven't reached consensus yet) think that we want the project in its own organization, rather than under openstack. We want to encourage external contributions from outside of OpenStack, therefore opendev would probably suit better than openstack.
This is open for discussion of course, but as I see it going, these are my personal thoughts.
Thanks,