This smells like accidental complexity. What's the point if you have to use the chain in a very specific way, and it can only achieve one thing? That could just

This smells like accidental complexity. What's the point if you have to use the chain in a very specific way, and it can only achieve one thing? That could just be made a single op. This seems like yet another way for ferrying code/state machines into the kernel. We already have bpf.