Ele Wands/Staves have no effect on dark element.

Elemental weapons actually specifically give -25% to their opposite elements and holy, not simply any element other than their own, and since elemental weapons don't exist in kMS, I wouldn't expect Nexon to make custom changes to them for the dark element.

That's not correct. "eleDefault" is how they're supposed to impose the penalty, they're not supposed to add penalties element by element using incRMAL/incRMAF/incRMAS etc with fractional values.