Which NAS features are you missing or refering to? Just samba/nfs mounts? Generally at the moment this feature is a bit hard to map, since various apps don't quite work well with files being changed behind their back through other means.
Setting up samba with the various workgroup settings was always a bit of a miracle to me. I may understand the use-case though, basically this is similar to a regular "storage box" type app then. Certainly something worth considering.
don't worry I also see this miracle from time to time and for now I'm using OpenMediaVault to make it happen
from the docker side, I sometimes use https://hub.docker.com/r/dperson/samba but I believe it is not LDAP ready.