I’ve been trying to figure out what kind of personal computing device would fit in these power envelope.

I dunno if this is what I want, but I like the idea anyway. ESP32 is like 500mW class or so (very rough estimate because I don’t care to look it up right now lol). So you can get more than 24-hours of processing with 4x AA cells or 18650 Li-ion.

I feel like there’s something ‘under’ the classic smartphone that might still be useful as a personal gadget. But alas, smartphones are an always in your pocket device today. Bluetooth keyboard + Phone would be a more practical note taking application.