I like the idea of a local (home, office) router with Blossom cache that keeps a copy of a blob, since by definition they can't change, and dynamically clear as blobs fall into disuse. This would relieve traffic from the larger cache and the WAN, and speed up multiple devices.

Also, another optimization could be that an actual file might be "owned" by multiple people who upload an identical file, such as a meme that is shared by multiple parties (such as yes.jpg), and this duplicate elimination would be completely automatic. You might not need to make any changes for this to take place, unless ownership meta goes into the hash. (Can we call it a filenym?)

One last feature that could really next-level this would be Timechain proofing. A particularly large or important Blossom server/router could routinely publish a Merkle hash as a Bitcoin transaction, and special requests can be made for the Merkle branch for certain important blobs (files or even Nostr events).