I think you're missing the point: 4:30am may be the right time for some, but that may be absolutely the wrong time for most. And it's not to do with finding a distraction free window. It's down to - as the article highlights - your body rhythm.

For instance, if I wake up at 6am I will spend hours in an awful state of catatonia. Often, I don't get over it the whole day. It's equivalent to how I felt when I suffered with depression. So, screw that.