I don't know about battery plating or it necessarily messing up, but I *do* know my battery life wasn't as good w/ an SBC kernel, as it is w/o it. My battery would stay on 100% a lot longer but overall it would drain a heck of a lot quicker. I've also read about more people having success using it w/ an extended battery, rather than stock. Keep in mind that this was just my experience w/ an SBC kernel, I know everyone's Evo's react differently to kernels and experiences will differ. Your best bet is to make a nandroid and give them a try.
That's impressive you got better life without SBC. Prior to using SBC I would always carry two batteries with me and have to swap around 2 or 3 in the afternoon. Are you using netarchy kernels or something else?
Like you said, just goes to show how everyone's phone is different.
Like he said there is only one way to find out how your battery/phone reacts to the kernel, give it a shot. I will tell to make sure you give each kernel you try 2-3 days to settle into your phone before you decide how it's working. Be sure to read the kernel starter guide I linked you in one of my posts so that you can understand what each setting is.
Enjoy.


