I fixed the battlevel voltage divider issue I had by reflowing another T1616.
On less good news the input current at 60uA out is 11.5mA, which is certainly high, low modes won’t have long runtimes. Most of that power draw is from the MP3432 in Ultrasonic Mode (30kHz min), if it was in Pulse-Skip Mode it would consume much less, but it requires 2 more resistor and there is a risk for audible noise at low input which I don’t really want to take.
Also, the MP3432 powers itself from its output when its Vin pin is <3.3V (that is the case with the 3V small boost supply), so it boosts to the LED Vf (7.5~8V) then the internal LDO regulates that to 3.3V. It would be more efficient to use a e.g. 3.5V supply. Unfortunately the next available voltage for the small boost converter is 4.5V, a bit better than 7.5V but another thing to consider is that the MCU current draw increases with higher VCC… in the end I’m not sure much can be done about this low mode power consumption.
Edit : we can see it when increasing Vin from 3.3 to 3.4V, the input current drops from 4.7mA to 3.9mA, then it increases to 4.05mA ar 4.5Vin, so a 4.5V boost supply would be potentially a bit better than 3V.