I have seen this suggested, and I know it can be implemented.
I have been using “Things” and like much of what I am experiencing with Agenda. However, one feature would make it so much better ( for me at least ).
I keep open items “On The Agenda”. Many of my tasks have checkbox lists. This is similar to “Things”. However, in that program, if I check off an item, it then is hidden, so only the pending items show.
In Agenda, I have many tasks and I currently have to do a LOT of scrollng through completed items. Moving stuff around is laborious, and can be confusing.
So … how about making it possible to have checked items hidden when the task is displayed in On the Agenda. Make the option a setup item. It sure would make this a more efficient display.