I haven't read the entire article thoroughly but I think "Queue management for inbound digital content" is something implemented in an SRS app called SuperMemo. The way it's intended to work is that you have content and over time break it down and through the scheduling system you eventually end up with extracts small enough to be made into SRS cards (though it's more complicated than that in actual use). It has a lot of weaknesses, mainly because a lot of it is based on features from IE (thus poor PDF support) but I still find it extremely useful. If I find any article that looks interesting I just throw it there and eventually I'll import it, go through it with incremental reading (https://supermemo.guru/wiki/Incremental_reading) and eventually dismiss it.

Edit: I also ought to mention, it has a very good priority/interval system for scheduling when I see things. Essentially things I give lower priority are less likely to show up and when I'm going through my material/doing my reps I'm more likely to see high priority material. There's a general issue that you find the thing you see soonest most shiny and thus a strong likelihood of overprioritizing new material but SuperMemo helps intersperse everything to prevent that.

It sort of can do the central search thing too to an extent, I can search through my collection of imported articles/cards and find stuff that's generally relevant to my interests. Though how useful it is depends largely on how long you've used the app. I am also reminded of the brain (https://www.thebrain.com/) but I'm not super familiar with it.

Have you heard of Ted Nelson's Xanadu? I've only looked into it a little but I was reminded of it when you talked about better reading.