One other thing I noticed today, while playing with this “feature” - sometimes the button backlight would get into a mode where it only blinked once at turn-on.
When this happens, the turn-off feature will not work. To get it back into two-blink mode, I long-press to ramp up to about 75% brightness. Apparently it single-blinks up to a certain threshold, and double-blinks for anything higher.