This is perhaps the most ridiculous storage system yet. It is totally impractical and super expensive, but it does show the power of lecterns. You flip to the pages you want on both lecterns, which selects shulker box from the system like coordinates.The orange circuits are redcoders (recently fixed for 1.16), the light blue line is an elongated redcoder, the yellow line simply preserves signal strength, the green circuit is an AND gate to detect if a shulker box is missing, the black circuit is an idiot-proofing system, and the blue line is where your input gets sent in. The glass towers and lines are for item transport.
The main takeaway from this isn't the storage system, which is ginormous, slow, and expensive. The main takeaway is the proof-of-concept this thing serves as.This thing has 225 distinct outputs that are all accessible from an interface 3 blocks wide.
Lecterns are amazing when paired with redcoders. Redstone now has the capacity to transmit much more complex information (15 different outputs instead of just 2).