What is your suggestion?

just another scale type you can modify with /scale
the value that is set for this scale will change the rate that you lose saturation/hunger when preforming actions that increase exhaustion such as sprinting, jumping, having the hunger effect, successfully hitting an entity(yeah, for whatever reason this increases exhaustion), etc.

I had this as an idea too lol, I also want this to be a thing.

I had this as an idea too lol, I also want this to be a thing.

Sadly I think development has stopped for pehkui (hopefully not permanently) so chances are it won't get added any time soon.