Interesting tidbit: After I created those outlines I’ve mostly never really looked at them again nor am I particular about adding new unprocessedsources to existing outlines. So much for it adding value. ¯\_(́ ◡◝ )_/¯ It takes time and aintnobodygottimeforthat.jpg.
My reading inbox is maintained in Obsidian alongside my zettelkasten and has 117 items currently in it. I don’t maintain a list outside of Obsidian anymore. If it is potentially interesting I toss it into the inbox. Some sources I spend a lot of time on, others a little time, some never get touched. Occasionally I go through and prune sources that I never got around to because they are no longer interesting.
Processing of sources typically happens incrementally. Work on source A a little bit, then sometime later on source B, then source C, then back to source A based on interest, etc. Over time the rough notes are grouped together and then spun out (using the Note Refactor plugin) into individual notes capturing the ideas.