This part seems to have extremely low power consumption compared to other CM4 devices. They cite 34 uA/MHz using built in buck regulators with inductors that appear to be about 0603 size. When running from 1.8 volts the current is specified as 51 uA/MHz when I assume the buck regulators aren't running or maybe they give less advantage.
The down side seems to be the part only runs at 24 MHz max using an internal RC oscillator. The only crystal is the 32.768 kHz osc. They have means of periodically calibrating the RC against the crystal osc.