Hey breaktru,
I really like your little buck/boost .44 mod, however I have a question: It looks like you are using a single 14500 (non high drain) battery; didn't you ever run into problems with the protection kicking in at higher voltages? Because I've made some mods with a boost circuit on a 14500, and they seem to work fine at the lower voltages, however above about 4.3 V the battery protection seems to kick in after a few drags. Obviously the 14500 I'm using doesn't like the higher current.
I think the way to combat this is to use a PWM circuit to "trick" the protection circuitry so it doesn't kick in (kind of like what the eGo does). However it looks like you were able to get the thing to work over the whole range, is that true?
Nice work on the mod, BTW.