How to check the PK of a foreign-key relationship without loading the related model; how to compare two objects

[merlinz01]

I have put my questions in the comments in the below code. I did not find answers in the documentation.

class User(Model):
    username = CharField(max_length=255, primary_key=True)
    organization: ForeignKeyNullableRelation[Organization] = ForeignKeyField(
        "models.Organization",
        related_name="users",
        on_delete=OnDelete.RESTRICT,
        null=True,
    )

    @property
    def is_admin(self):
        # Does this load the organization model?
        # Is there a way to check the foreign key itself for being null without loading the referenced model?
        return self.organization is None

    def may_create_user(self, user: "User_Pydantic"):
        if self.is_admin:
            return True
        org = user.organization
        if org is None:
            return False
        # Is this the correct way to compare two models?
        # Does tortoise do original-object-return so that we can test using `is`?
        return org == self.organization