Normally on Android you can only use one evernote account.
But Knox on Samsung Note 3 gives me a second evernote with a second account.
To use a second one you would have to wipe the first one and install the second one. This is too much effort and time delay for the new sync.
On a PC you may switch between accounts. As a premium user this is quite handy.
With the second Knox-Evernote I have in fact two separated evernote applications running (what is even more than on a PC).
Switching is as fast and easy as with any other app inside android.
Another way I could imagine but did not test should work on each android machine: Open the second evernote account inside a web-browser.