Hello.
Thanks for the code. Do you still have any code that works on the Arduino Leonardo but does not work on the A-Star 32U4 Micro? We have not investigated low-power code on the ATmega32U4 but I recommend reading the ATmega32U4 datasheet. I also recommend trying to write your code so that the AVR wakes up when USB power is present, so that the A-Star can be easily reprogrammed over USB. This StackOverflow thread has some general advice that might be useful in reducing power consumption.
-Tony