Some messages will never be deferred:
commandNotHeard - if a command is not heard, it will never enter an actor's command queue; the error is given immediately in response to the command entry.
refuseCommandBusy - same as commandNotHeard
noMatchDisambig - interactive disambiguation will not happen in a deferred response situation, so it is impossible to have an interactive disambiguation failure.
disambigOrdinalOutOfRange - for the same reason noMatchDisambig can't be deferred.
askDisambig - if we couldn't display a message, we definitely couldn't perform interactive disambiguation.
askMissingObject - for the same reason that askDisambig can't be deferred
askUnknownWord - for the same reason that askDisambig can't be deferred.
npcDeferredMessagesDirect : npcDeferredMessages