"PKM Loading overrides" prompt options

[xinceras]

I'm transferring Pokemon from Emerald to Platinum. When I use "Tools --> Data --> Load Boxes" PKHeX opens this prompt:

PKM Loading overrides:

Yes - Modify .pk* when set to SAV
No - Don't modify .pk*
Cancel - Use Current settings (Yes)

There's a mod post from 6 years ago that says it's supposed to "fake a trade" if you choose "yes". But I've tested both yes and no, and I don't see the difference between the two. Either way the Pokemon says it came from PalPark and lists the original game and Original Trainer.

Is it supposed to do something else? Does anyone know exactly what the "Yes" and "No" options here are supposed to do?

[Kaphotics]

It's relevant when the PKM format has data that is normally updated by the game when traded. Current friendship (Gen2+) gets updated, eggs get their met location set to Link Trade (Gen4+), handling trainer data gets updated (Gen6+).

PKHeX gives you the option of skipping the game's trade updates when importing the data. Skipping it can result in mismatched data, but will keep the data exactly as it was stored in the PKM file.