What's thrown me is that I couldn't find in the OJS 2.4 interface an place to create / login as ROLE_ID_PROOFREADER or ROLE_ID_COPYEDITOR , all I see are 2 references to these in the install/upgrade.php file.  That's why I concluded that it is impossible to test these.  However, I did leave the code in in case I was wrong, or to enable them for testing if these rolls should be handled in OJS 3 ?  

If I toast them, then I have taken away the simplicity of referring to that tentative knowledge about the state of affairs.