Hi magicians

I 'm testing the various options for logon to a Magic desktop app.

In Magic Knowledge Center, I 'm reading the article "How Do I Use My Windows Login Name to Log on to Magic xpa? (Magic xpa 3.x)"
http://kb.magicsoftware.com/articles/bl_Reference/How-Do-I-Use-My-Windows-Login-to-Log-on-to-uniPaaS-xpa-3x

As far as I know using the User=%USERNAME% as a command line parameter and setting System Logon to None is enough to do the job .
Still, In bullet #4 I read: "In Options->Settings->Environment->System, set System Logon to User Name".
Is it due to inaccuracy of MSE's documentation or am I missing something?

Also, is there a safer alternative to the %USERNAME% environment variable? (this variable can be manually set to any name)

Thanks in advance
Avgerinos