power up RF calibration options

[geo.espressif]

I'm setting the RF powerup option by generating a new user settings .bin using the ESP Flash download tool 2.3. I'm setting the full calibration option (byte 114 option 3), and flashing my device. I can't see that any RF calibration is happening though, and I need it to happen every time the device boots.

I have a 1mb flash and I'm putting the generated .bin at 0xFC000 as per the IoT document.

Any idea what I'm doing wrong? Should the calibration happen each time the device is booted?

James