You can, and there's a specific flag to set on nd/ra to tell the client to get other information from djcpv6. But so far I've not made it work and also, it likely won't work on android.
Really the way forward is for routers and devices to implement the same options as exist on dhcp. But, time will tell how that gets on.
This is a weakness of ipv6 but it's really the lack of widespread implementation that's behind this. If we were all using it, there would be more onus to get this stuff working.