Changing AP system from 4 to 8 (or even 12)?

There is a misunderstanding here. In your concept, this will be Heavy’s skill.

For the current RB, the width of the sector cannot be adjusted.
In my concept, sector width (strict) = weapon accuracy (+/- penalties).
It will be Mechanics, not just for Heavy. For example, a skill for a Sniper with a pistol, or rebuild a skill: