iOS Siri: Untimed to-dos in OmniFocus, timed to-dos in Alarmed. Hope to distinguish?

Context: I only use OmniFocus on the iPhone.

I use OmniFocus for untimed to-dos: for things that need to be done AROUND a certain day or time, but not precisely. I use Alarmed for timed to-dos: for things that need to be done precisely at a certain time.

When I tell Siri “remind me tomorrow to take out the trash,” I want that to be taken in by OmniFocus. when I tell Siri “remind me at 5:30 PM tomorrow to take out the trash,” I want that to be taken in by Alarmed.

Currently, no matter what I do, it’s taken in by the app I happen to use next. Neither distinguishes at all.

I think I’m misunderstanding how Siri should be used. How can I have Siri make some to-dos only for OmniFocus and others only for Alarmed?

Thanks!