Model in Built Filters (polymorphic identity?)

Problem I'm trying to solve
I have a table that really contains multiple item types. In SQLAlchemy I would make multiple models from this using Polymorphic Identity. I can't figure out how to do so w/Tortoise or if there exists an API for this at all.

Desired Solution
I would like some method to build multiple models from one table based on inbuilt where statements. I also want model associated inbuilt filters in general. For example, deleted_flag='N' so that when using a model the filter is already present. The reason being I'm trying to make these models abstract complexity for more junior devs and automation support.

Alternatives Considered
I have made this happen via SQLAlchemy. Here's an example:

class ExecutionPlanModel(Base):
    __tablename__ = 'tesexecplan'
    __table_args__ = {"schema": "tesreport"}

    objref = Column(String, primary_key=True)
    expt_id = Column(String, primary_key=True)

    __mapper_args__ = {
        "polymorphic_on": case([
            (expt_id.like('MP%'), "maskplan"),
            (expt_id.like('DMLP%'), "dmlp"),
            (expt_id.like('DP%'), "device"),
        ], else_='dmlp'),
        "polymorphic_identity": "executionplanmodel"
    }

And a concrete class from the polymorphic base.

class MaskPlanModel(ExecutionPlanModel):

    maskname = Column(String, name='masklayername')
    tapeoutprojectobjref = Column(String, ForeignKey('tesreport.testapeoutproject.objref'))

    tapeoutproject = relationship("TapeoutProjectModel", back_populates="masks")
    # dmlps = relationship('MPAssociation')

    __mapper_args__ = {
        'polymorphic_identity': 'maskplan',
    }

    def __repr__(self):
        return f"<MaskPlan(expt_id='{self.expt_id}')>"

No Tortoise files, tests, or entry points are named. Start by reviewing the SQLAlchemy polymorphic identity examples in the issue and the existing Tortoise model-inheritance and filtering APIs; clarify whether both filtered models and polymorphic identities are in scope. Done would require an agreed design and tests covering the requested behavior.