As far as I know it will clear the heads cleaner.  As far as the pros using this pattern on pattern D, I don't know.

how would you drill a ball for forward poll, someone told a lot depends on placement of balance hole and pitch of balance hole.

If you need length, the term you are looking for is "high RG drillings", not forward roll. . Forward roll drillings are also known as heavy roll drillings. Places the core in a more stable position. Mainly used for extreme wet-dry conditions and sometimes in heavy carry-down. (Pin to PAP distance is around 1')
Place, width, depth and pitch of the balance hole are of course very important. But It is used for fine tuning the reaction next to the purpose of bringing the ball back to legal. Pin to PAP distance is the primary factor to lay out a ball for a desired length and flare potential.

Hope this helps..
Burak