So as far as I can make out, when I load a new application into the flash, the NRF52 will attempt to first load a secondary memory space and if successful, it will then replace the original image with the new one. If it is not possible to do this, it will simply overwrite the existing image.
Obviously, the first method is far more error-resilient than the other, even more so once we get to the state of wishing to replace the SD or the bootloader.
What I have not been able to determine is: How do I know which method the upgrading process used? I know it will automatically select the right one, but it would be nice to know which is happening, for two purposes: If something blows up, we know where we were and what the state of the chip is now. And also: If we go from using dual to single page upgrading, we should consider whether what we have added is worth the increased risk.
Thank you,
Dan