There are various reasons to different battery life, but most important is that you don't have C-states active. And including C-states in a third party kext is a bigger project.
The battery-profiles (and all the customizing features) are removed as most people ignored them and didn't make use of them, instead I want to simplify it as much as possible. Right now it doesn't work different whether on AC or battery, but in a later version I will add it back (with a hardcoded profile).