What if you give each slot independent command pins but not a complete memory channel? What if you use a similar technology to registered or load-reduced memor

What if you give each slot independent command pins but not a complete memory channel? What if you use a similar technology to registered or load-reduced memory, but put the register on the system board instead of the DIMM so it's in front of multiple DIMMs that then share the channel into the processor but not the traces on the system board? This may also allow higher capacity DIMMs in consumer systems.