A boost circuit powering the MCU seems like a recipe for high parasitic drain. But I could be wrong. I would love to see any ramping UI running whatever MCU necessary for a NiMH cell to work with low parasitic.
Bare bones, watered down Anduril Ramping UI
From off:
1H moon (pause for 1.5-2s then continue ramping)
1C memory
2C high (current chosen which naturally stabilizes at ~55-60C tail-standing w/o any airflow)
From on
1H ramp up
2H ramp down
1C off
2C turbo (timed step down for simplicity - another 2C returns to previous mode - manual restart if desired)
No other fluff. It’s an AA light, so no blinkies of any kind make sense. No aux LEDs draining the small cell. I can’t see how this UI couldn’t be written to fit within even the smallest of MCUs