Proficiency XP

[Xander Tyrann]

Does anyone know the mechanics behind what affects the proficiency XP you gain?

I know KOs do but I don't know to what degree. And that's about all I know.

As a very quick test I checked the number before and after a random stage 4 battle and I gained ~11k XP from 1380 KO without any modifiers like the training weapons or the herb.
So its obviously not 1-1.

Does difficulty affect it? Do you gain more for officers? Does that item that boosts rewards affect it? Does the stage level affect it? anything else?

I know there's also that herb but it says it only applied for the first 100 KOs which seems a bit low for 5k when I'm killing thousands of soldiers... Is there a way to maximise that effect?

Couldn't find much information around it so I think I would ask some questions.

[ruff1298]

After 1st story route clear, you unlock Training weapons with a 30% profiency boost, at the cost of no blocking, only parrying.