INSERT INTO test_table (cnt) VALUES (1), (2) RETURNING id
if a portal is used to get the results then the CommandStatus
IIUC the portal is not optional if you including the RETURNING clause.
From my testing it isn't required.
There is no CommandStatus message in the protocol, the desired information is part of the command tag returned in the CommandComplete message. You get that at the end of the command, which has been defined as when any portal produced by the command has been fully executed.
I could argue that the insert is fully completed whether I read the data or not.
You probably should add your desire to the Version 4 protocol ToDo on the wiki.
