One model, different schemes

[drnextgis]

I have two models: Projects and Subscriptions. Each project can have multiple subscriptions (one-to-many). I started from this code:

class SubscriptionSchema(ma.ModelSchema):
    class Meta:
        model = Subscription

class ProjectSchema(ma.ModelSchema):
    class Meta:
        model = Project

But in this case I could create new subscriptions from Project but schema.dump returned just object ids.

Write (OK):

>>> project = Project.query.get(1)
>>> schema = ProjectSchema(partial=True)
>>> project, errors = schema.load({"subscriptions": [1, 2]}, instance=project)
>>> schema.dump(project).data
{'id': 1, 'subscriptions': [1, 2]}

Read (not OK):

>>> project = Project.query.get(1)
>>> schema = ProjectSchema()
>>> schema.dump(project).data
{'id': 1, 'subscriptions': [1, 2]}

To overcome that issue I created a new schema:

class ProjectSchemaNestedSubscription(ProjectSchema):
    subscriptions = ma.Nested(SubscriptionSchema, many=True)

and now I'm using different schemas for different REST API endpoints:

def get(self, project_id):
    schema = ProjectSchemaNestedSubscription()
    ...

def put(self, project_id):
    schema = ProjectSchema(partial=True)
    ...

Is this a right way to do what I need? Or maybe it is possible to do the same using just one schema? Thanks.