You can do this protocol using a neutral, wide, or underhand grip. I like to use a different grip each time to create a different stimulus. The isometric is performed at the bottom position because this is the point of the ROM where most people cheat.
You multitaskers out there will love this movement as it allows you to work the rectus abdominis, the obliques, and the serratus at the same time. Too bad the rest of your life isn't as efficient.