Personality System Data Collection [WiP]

Not sure if its been mentioned, but Evolution Rings give 5 Diligence each. I have 10 diligence right now before profession is out...5 from each evo ring.

This confuses me as to how dilligence works tho. If it's not like charm exp that remains even after you unequip the stuff, then in theory switching rings or whatever else gives dilligence could delevel it?

And I have another question if anyone knows. Is the "double mastery chance" effect from dilligence referring to the chance on passing mastery books or some % on higher attacks because of weapon masteries?