Akodo Senzo + Ikoma Igawa

Akodo Senzo reads: Battle: Target another Personality and choose one of his base abilities; he may use it a second time this turn. You may take another Battle action.

Ikoma Igawa reads: Reaction: After engaging in a battle, if Igawa is in the current attacking army, discard a card: The Defender chooses and discards a card from his hand.

Situation:

Akodo Senzo and Ikoma Igawa assign to province A togther. Akodo Ryozo assigns to Province B. Attacker resolves province A first choosing not to react with Ikoma Igawa. Defender passes and the attacker uses Akodo Senzo and targets Ikoma Igawa to have the ability to use his reaction twice in one turn. With his additional follow up action the attacker uses Unpredictable Strategy to switch the location of Ikoma Igawa and Akodo Ryozo. The Defender passes and the attacker passes as well.

The attacker then chooses to resolve Province B and reacts with Ikoma Igawa and then wishes to react with him again seeing as Akodo Senzo's ability grants him the ability to use a base ability twice in one turn.

Question: I know traits cannot be triggered twice to the same trigger but since reactions are OPT as a standard action, can this situation be done? If not, what is the justification behind the once per trigger for reactions?

can this situation be done?

No, per Timing sequence: "A player may not use the same copy of a Reaction [...] more than once to a single trigger."

However the Attacker could have used Ikoma Igawa's Reaction after engaging at the battlefield in province A, then he could have used Akodo Senzo and Unpredictable Strategy as suggested above in order to use Igawa's Reaction a second time after engaging at the battlefield in province B.

what is the justification behind the once per trigger for reactions?

Because the rules say so.