I agree that a raised logo would look very cool, but may be expensive. Perhaps "reverse-engraved"?? I think machining would be out, because that would probably cost as much as the rest of the knob. You would also have a minimum radius, too, because of the end mill, and I think you may lose the super sharp edges of the logo. Perhaps you could use a mill small enough to not leave a noticeable radius, but then you wouldn't be removing much material per pass.... Ahh, I'm rambling.
The knurl is vertical only. I had (10) knobs made with a close spacing like what is used on my current aluminum capped knobs, but the rest of the first batch I had done with the large pitch knurl as shown in the first set of pictures. This larger pitch is because I tried to copy the knurl spacing of the original Arkanoid knob, and it came out pretty close.