Constructed Pugilist and magic weapon abilities

[Nash O'Dalthir]

Hello, I'm Nash O'Dalthir and i need some advice for the Constructed Pugilist (Brawler Archetype)

I've asking to 2 DM after rules to enchant my Constructed Limb with the magical ability "Impact"

The 2 DM's answer wrote:

"You can't put Impact magical abilitie on because your limb is a light melee weapon."

But i seen 2 threads where some members put Impact on the Constructed Limb :

=> Constructed Pugilist & Size Effect
=> Ballpark figure for Ennemy HP

So i need a official and complete advice : Can we put the Impact magical Ability on a Constructed Limb ? Yes / No ? + RAW/RAI ? + Explanation.

Thank you for you experiment.

Ps : Sorry, i hope this is understanding, because i don't speak english several time.

[Dragonborn3]

Constructed Pugilist wrote:

She treats the limb as a light weapon and is proficient with it.

Impact wrote:

This special ability can only be placed on melee weapons that are not light weapons.

Your GM is correct.

[Nash O'Dalthir]

Yes... and that why i'm asking for more advices because wording sentence is unclear

Constructed Limb (Ex) wrote:

She treats the limb as a light weapon and is proficient with it.

I'm agree with this, RULE AS WRITTEN, ....But in the same Ability

Constructed Limb (Ex) wrote:

For the purpose of rebuilding the limb as a masterwork weapon, rebuilding the limb out of a special material, or adding certain magical special abilities to it, the limb counts as a one-handed melee weapon

So if we follow the sentence Count as a one-handed melee is clearly different than Count as a light melee weapon. Right ?

So which purpose has the highest priority between treat and count ?

If these 2 purposes have same priority so a Constructed Limb is a Light Melee Weapon AND a One-Handed Melee Weapon no ?