Some of these examples are trivially equivalent to queues and queueing theory tells us that 100% utilisation results in unbounded queue lengths, and is therefor

Some of these examples are trivially equivalent to queues and queueing theory tells us that 100% utilisation results in unbounded queue lengths, and is therefore bad. The interesting thing would be to try to see if these other situations that on the surface sort of smell similar (serialisation and distribution systems, for instance) are actually isomorphic to the extent that the same proofs apply.