MCE::Shared was made to complement MCE and other parallel modules. After review, I realize that it was never the intention for MCE::Shared to be 100% paritiy with MCE regarding chunking. Currently, MCE::Shared has limited chunking capabilities. But that was possible because of little effort, simply by enhancing read with (k,m) suffix. Unfortunately, full chunk IO capability inside MCE::Shared is not likely anytime soon over what is possible now.
Many examples were provided for writing output orderly. Another one was made moments ago, here. Workers there write directly to the output handle, orderly and serially, very much like testa.