Metalware and PD

there's pd on the metalwear kits for "heavy" armor types, so in regards to getting X levels on a heavy helm item and X levels on a heavy boot item; are they still calculated at the same time or added due to level of metalware? is there any damage reduction change at higher levels(there are 5 PD-able slots)?

http://mabinogi.wikiwiki.jp/index.php?%C1%F5%C8%F7%2F%BA%D9%B9%A9

That's a good question, and since metalware is implemented it should be investigated more.