We measured 15mA of quiescent current draw on the 5V rail of the sensor (with the ESP32 held in reset). We traced it to the following:

• 2x power indicator LEDs – approximately 2.6mA each, totalling 5.2mA
• 2x AZ1117C voltage regulators – datasheet specifies 4mA (typ) to 6mA (max) of quiescent current draw.

With this in mind, we swapped the AZ1117C to AP2114, which have a maximum quiescent current of 90uA.

Masking off other components before removing regulator with hot air

Getting a crude current estimation from the power supply

We should be able to cut quiescent current down to less than 1mA (when powered from the 5V rail) if we disabled the LEDs. Although quiescent current is only a small part of the overall power budget, the 15mA we were observing is still a fairly large amount of power just wasted.