Openstack SelfService network with IPV6 subnet from provider network

I am installing an openstack infrastructure but i have an issue with the selfservice networks and the ipv6

On my provider network i have the fddd:3138:5d15:18::/64 subnet which is my local server range.

I've managed to make the ipv6 works in a SLAAC-SLAAC configuration with a second /64 subnet (fddd:3138:5d15:180::/64) and a static route in my switches (by defining the provider subnet + gateway and selfservice subnet)

But my question is : Is it possible to use the "none - slaac" mode (or other) in my selfservice network with the "provider range" fddd:3138:5d15:18::/64 and let my external router advertise the RA for the openstack instances ? Or is it only possible on a "provider" network without a neutron router ?

Just like that i don't have to create a second subnet for each vlan we have.

I hope it's understandable.

Thanks.