Answer: when the user is being lied to...

AIO mode is a specific mode inbuilt into RevB X-Rite i1D3 probes.
It is a specific mode that operates within the firmware of the RevB probes.
It is not something that can applied within the calibration software.
Any software manufacturer that state they have implemented AIO mode, but neglect to tell you it is not really AIO mode, but a fake process within their own software are, well, not really telling the truth...

And worse, as it is not really AIO mode, it slows the probe operation rather dramatically...

As has been said before, there are lies, damn lies, and some company's marketing.

Steve