There was a question on the OmniGroup Discourse Forums the other day about seeing completed items in OmniFocus, but just the last two days’ worth. While this can’t be done with Perspectives, it can be accomplished with the new Shortcuts integrations.
Now that Agenda supports both re-organization of sidebar items and the creation of projects via URL scheme (woohoo!), I have aligned my project structure between it and OmniFocus, allowing me to have consistent ways of reflecting reference and action material.
On episode 12 of the Nested Folders podcast, Actions vs. Reference, I mentioned a shortcut to create projects in both Agenda and OmniFocus. This is awesome, because it allows me to have complementary and align organizational structures for both action/task management and reference material.