InteractionEmailMoveToWorkbin chain of commands

[mzak2]

I would like to know why the code:

commandManager.InsertCommandToChainOfCommandBefore("InteractionEmailMoveToWorkbin", "IsContactModified",
new List<CommandActivator>()
{
    new CommandActivator() { CommandType = typeof(MyCommand), Name = "MyCommand"}
});

executes well if the task in the .module-config is:

<task name="InteractionWorkspace.Voice.canUse" clickOnceGroupsToDownload="Contacts,OpenMedia" modulesToLoad="MyModule" />

but fails if the task is:

<task name="InteractionWorkspace.Email.canUse" clickOnceGroupsToDownload="Contacts,OpenMedia" modulesToLoad="MyModule" />

In the last case it always inserts my custom command at the end of the command chain but not at the beginning as requested.
Workspace Desktop Edition v8.5.130.4