https://github.com/apache/airflow/pull/12139 added some new params to the scheduler -- we have "cursory" docs for them in the comments in the config file, but we should have a more details docs in the scheduler.rst page.
airflow/jobs/scheduler_job.py
synchronize_session=False,
        )
        for ti in executable_tis:
            make_transient(ti)
        return executable_tis
    def _enqueue_task_instances_with_queued_state(self, task_instances: List[TI]) -> None:
        """
        Takes task_instances, which should have been set to queued, and enqueues them
        with the executor.
        :param task_instances: TaskInstances to enqueue
        :type task_instances: list[TaskInstance]
        """
        
        for ti in task_instances:
            command = TI.generate_command(
                ti.dag_id,
                ti.task_id,
                ti.execution_date,
                local=True,
                mark_success=False,
                ignore_all_deps=False,
                ignore_depends_on_past=False,
                ignore_task_deps=False,
                ignore_ti_state=False,
                pool=ti.pool,
                file_path=ti.dag_model.fileloc,
                pickle_id=ti.dag_model.pickle_id,
            )
            priority = ti.priority_weight
            queue = ti.queue