Today I populated another regulator PCB, leaving out the components that won’t be in the final design. The standby current at 6v input level is now only 1uA! My latest estimate of the quiescent current of the toggling/control system is ~50uA. I’ll refine my numbers as testing verifies them. I’m considering placing the pads for, but not populating the indicator LED in the final design so as to save a few milliamps, but on the other hand, one could always remove the LED or cut a trace.

I just tested the quiescent current of my prototype circuit, minus the indicator LED, and it is 38.6uA! With no indicator LEDs the current jumps to 1.9mA while the button is being held down.