In the versions before the new one, when I created a check list of tasks in a note, I could create a reminder from every line that I wanted, and where I did that, a small »clock« sign appeared to show that this item is already linked to my task list/calendar-system (I use BusyCal where both tasks and event appear in the same picture).
This has become by far the most important feature of Agenda for me.
Unfortunately, it is somehow broken now. I still can create a reminder (although regrettably no longer from the cog wheel menu, which is much less practical now), but the clock sign appears no longer. So I have no visual cue, which tasks are »active« and which one not yet.
I must say I heavily regret having updated to the new version. The version before was almost perfect; I should have stayed there.