Selecting Tray Filament in Handy vs Bambu Studio vs Bambu Spools?

Bambu Lab Software
1

When selecting Filament for an AMS tray in Bambu Studio, it is possible to select also PA Profile (K).
When doing the same thing from the Handy App, the PA Profile is not available to select.
(and I think the same is also on X1C display, but not sure, I have P1S)

  1. What ends up being the difference then if I select from Handy and then print from Bambu Handy vs. Selecting the PA profile from Bambu and printing? In the first case then the K factor won’t be considered so printing will be w/o calibration?

  2. And what happens in the case of Bambu filament that fetches the info from the spool? It doesn’t allow seeing or setting the PA calibration.
    Does it have inside all the calibration information for all nozzle sizes for example?

  3. Does the printer need to know the PA calibration factor for anything? Or does it only affect the g-code generated by the slicer?