How can I compose a single Schedule from different places in code through some kind of extension points?

My use case is that:

• I want there to be a limited amount of Schedules, because each Schedule needs its own bin/console messenger:consume scheduler_NAME worker running. I want to keep the infrastructure simple without running many different workers.
• I want to add recurring messages from any place in the codebase

The "convenience" attributes #[AsPeriodicTask] and #[AsCronTask] do what I am looking for - they add new triggers to the schedule. However, I couldn't find a way to be able to add new triggers through "rich" PHP code where more customization can be made. See code below.

This defines the foo schedule with a single trigger:

#[AsSchedule('foo')]
class FooSchedule implements ScheduleProviderInterface
{
    private Schedule $schedule;

    public function getSchedule() : Schedule
    {
        return $this->schedule ??= (new Schedule())
            ->with(
                RecurringMessage::every(
                    '10 seconds',
                    new FooMessage('Hello'),
                )
            );
    }
}

Now, in a different service, I would like to add another trigger to the existing schedule. I tried two approaches:

1. Through another #[AsSchedule] attribute.

#[AsSchedule('foo')]
class ExtendingSchedule implements ScheduleProviderInterface
{
    private Schedule $schedule;

    public function getSchedule() : Schedule
    {
        return $this->schedule ??= (new Schedule())
            ->with(
                RecurringMessage::every(
                    '20 seconds',
                    new FooMessage('Extended hello'),
                )
            );
    }
}

This does not work (as could be expected) and only one of the duplicate foo schedules will be registered - the other is completely ignored.

2. Through dependency injection of the FooSchedule in a service. This one I thought should work, but I get container build errors.

class SomeService
{
    public function __construct(
        FooSchedule             $fooSchedule,
    )
    {
        $fooSchedule->getSchedule()->add(
            RecurringMessage::every('20 seconds', new FooMessage('Extended hello'))
        );
    }
}

This results in:

Cannot autowire service "SomeService": argument "$fooSchedule" of method "__construct()" references class "FooSchedule" but no such service exists.

Looking at the FooSchedule class, which is registered as a service, I see that it is overwritten in the container and assigned a different class!

$ bin/console debug:container FooSchedule

 // This service is a private alias for the service scheduler.provider.default

Information for Service "scheduler.provider.default"
====================================================

 ----------------- ------------------------------------------------------------------------------------------------------
  Option            Value
 ----------------- ------------------------------------------------------------------------------------------------------
  Service ID        scheduler.provider.default
  Class             Symfony\Component\Scheduler\Schedule
  Tags              scheduler.schedule_provider (name: default)
                    container.decorator (id: FooSchedule, inner: scheduler.provider.default.inner)
  Calls             add
  Public            no
  Synthetic         no
  Lazy              no
  Shared            yes
  Abstract          no
  Autowired         no
  Autoconfigured    no
  Factory Service   scheduler.provider.default.inner
  Factory Method    getSchedule
  Usages            FooSchedule
                    SomeService
                    .service_locator.GQvl1cG
 ----------------- ------------------------------------------------------------------------------------------------------

My FooSchedule is hidden behind a decorator (I think) and the DI fails.

So, given that these do not work, what is the recommended and supported way of composing schedules? I have scoured the documentation and all the examples I have come across only show a simplistic case where the schedule is defined in one class.

I am thinking that I could collect all the "extending services" myself through custom tags and autowiring in the Schedule class, but it feels there should be a more out-of-the-box way to do that.

Thank you