What I did: I have two different calenders and 4 reminders setup on my MacBook.
What happened: When I try to schedule from Agenda the dropdown did not give me any options for different calender or reminder. Agenda schedule it in the default calender same goes with the reminder.
What I expected: I should be able to select different calender or reminder from Agenda.
Things that might be helpful to know (Agenda version, OS and model, etc):