Yes, you can do extra easy all the time if you like. Or you can intersperse it with red or green. Just make sure you choose just one plan (red, green or e-e) at the start of each day and stick with it.
I had a couple of months when I did EE every day and it was great. Am trying to do mainly red at the mo cause it's better for my IBS but as long as you're having lots of Super free foods, there's no reason not to do EE if it duits you x