Best regards, creator.
I have tried the 2 punches with two different commandos (beret and sniper, 1 and 2). I guess it wasn't simultaneous enough because I got insta alarm. Didn't try more than 2 times the simultaneous punch thing. I trust you that it's doable, but I don't really want to lose my time with that.
I understand from your answer that the easy mode is not trying to be faithful to the original, so the mod is simply not for me (I enjoy some hard modes, but I thought easy was a least faithful).
Your work is nonetheless impressive, I will perhaps check it again in a few years as I like to replay games.