you could try calibrate, but i doubt this will solve the draining problem. boeflla kernel should come with boeffla config app v2, try some different settings for the kernel in config app, maybe the kernel needs to settle for a while..
im using also boeffla kernel atm. but mine is for sammy (TW) based roms and im happy with the battery life that i got now. Im easily getting a day (24 hours) out of the battery after having fully charged and sometimes even longer.
my settings in B. config app, if its gonna help you:
governor = pegasusq
governor profile = pegasusq-speedmod
ext4 tweaks = ON
GPU freq. profile = 160/266/350/440/533 (default)
system tweaks = boeffla tweaks (enabled)
before sammy rom, i was on aosp/LiquidSmooth rom and imo it has the most awesome battery life on stock kernel amongst all the aosp roms for i9305, sometimes i got 2 days on screen, perhaps you should try another cm based rom like LS or Archidroid. I think the stock kernels of those two are build with sabermod toolchain, which is great