SQLAlachemy eager loading in CTE recursive query for a self-relational model which is a declarative model

models.py

class Network(Base, IdMixin, TimestampMixin):
    ip_address = sa.Column(IPAddressType, nullable=False)
    netmask = sa.Column(IPAddressType, nullable=False)
    name = sa.Column(sa.String(64), nullable=False, default=lambda: str(uuid.uuid4()), unique=True)


class Host(Base, IdMixin, TimestampMixin):
    name = sa.Column(sa.String(64), nullable=False)
    addr = sa.Column(sa.String(256), nullable=False)
    is_compromised = sa.Column(sa.Boolean, nullable=False, default=False)
    meta = sa.Column(JSONB)


class NetworkHost(Base, IdMixin):
    network_id = sa.Column(
        sa.Integer,
        sa.ForeignKey(Network.id, ondelete='CASCADE'),
        nullable=False,
    )
    network = orm.relationship(Network)
    host_id = sa.Column(sa.Integer, sa.ForeignKey(Host.id, ondelete='CASCADE'), nullable=False)
    host = orm.relationship(Host)

    @declared_attr
    def parent_id(self):
        return sa.Column(
            sa.Integer,
            sa.ForeignKey(f'{self.__tablename__}.id', ondelete='SET NULL'),
            doc='When it is null, it means TEP agent is running in the host',
        )

    @declared_attr
    def parent(self):
        return orm.relationship(
            self,
            remote_side=self.id,
            backref=orm.backref('children', cascade='all'),
        )

scratch.py

from sqlalchemy import literal, orm

from db.base import Session
from db.models import Host, Network, NetworkHost

hierarchy = (NetworkHost.query
             .filter(NetworkHost.parent_id.is_(None))
             .with_entities(NetworkHost, literal(0).label('level'))
             .cte(name="hierarchy", recursive=True))

parent = orm.aliased(hierarchy, name="p")
children = orm.aliased(NetworkHost, name="c")

hierarchy = (hierarchy
             .union_all(children.query
                        .filter(children.parent_id == parent.c.id)
                        .with_entities(children, (parent.c.level + 1).label('level'))))

h = (hierarchy
     .join(Network, Network.__table__.c.id == hierarchy.c.network_id)
     .join(Host, Host.__table__.c.id == hierarchy.c.host_id))

edges = (Session.query(h)
         .select_entity_from(h)
         .with_entities(hierarchy.c.id.label('id'),
                        hierarchy.c.parent_id.label('parent_id'),
                        Network.id.label('network_id'),
                        Host.id.label('host_id'),
                        hierarchy.c.level.label('level')))

for obj in edges:
    print(obj.id, obj.parent_id, obj.network_id, obj.host_id, obj.level)