On the other hand, the error correction below layer 7 does does head of line blocking anyways. DSL is a good example, when "interleave" is on it adds ~40ms of l

On the other hand, the error correction below layer 7 does does head of line blocking anyways. DSL is a good example, when "interleave" is on it adds ~40ms of latency to reassemble packets. Cellular is less severe but similar. Fixing head of line blocking at layer 7 won't un-interleave the packets.