1. Is your "4000" ball done via 500/4000 or 500/1000/2000/4000?
If it's 500/4000, then do the 2nd sequence. It will do just what you need. Use fresh pads or be careful. A used 4000 grit pad puts a shine on the ball.

2. I would not be inclined to apply Rough Buff over a 4000 grit sanding. It is usually intended to smooth out very rough surfaces, like 500, 750 or maybe 1000 grit. When you apply it to 1500 grit and above, you get the equivalent of a high polished ball. You could try sanding it to 1000, then apply Rough Buff, but it takes a seasoned eye and a gentle touch to watch what you're doing and remember what the 4000 sanded looks like and to see that you've gone just a little finer without getting into the polished phase. I don't recommend this unless you experiment first.

3. Applying polish to 4000 grit gets you lot of length and the backend depends on your release, the actual ball and the oil. Can be super flippy or arc-y or anywhere inbetween.

I see 3 alternatives for a little more length:
a. Sand with a White Trizact pad with lots of water as per usual. White Trizact is a notch finer than 4000 grit. It has been estimated as anywhere from 5000 to 10000 grit. My best guess is 6000/7000 grit range.
B. Sand it to 1000 - 1500 grit and apply a non-abrasive polish, like Valentino's Snake Oil, lightly and check the reaction. Add more polish VERY lightly as needed.
C. Apply a non-abrasive polish to the 4000 grit sanded surface by hand, with maybe a dime sized portion of polish for the entire ball. Buff it by hand also, gently. If you do it right, you should have a hard time telling that you've applied any polish at all. If you did it wrong, it looks polished. Start over.