Not really keying in on any one particular pitcher but I would call Lincecum's motion a "leap". Most pitchers rotate off the rubber, rolling over onto the instep then the toes. In this motion, the toe can move out by a couple of inches, depending on the motion. To truly have a drag "line" before landing, you would need to do what Lincecum does.
How early would be too early? It varies in the pros, of course, but most begin the sideways movement of the centre of gravity either at or just before peak knee lift, avoiding the infamous "balance point" and facilitating momentum generation.
OK, I think I got that double negative there. So, they DO encourage it? If so, good.