Based on my experience....both as a track official, starter and athlete (I'm in a local College Hall of Fame).....
His length of stride, gait and style show nothing out of the ordinary that would be called 'enhanced' by his prosthesis. I am going to change my mind.
IF he manages to make a qualification time he should be allowed to compete.
He is simply the best para athlete and he is good enough to compete with the big boys. If his type of 'mod' was so good there would be more of them trying to compete. There aren't.
His mod is like replacement for his natural legs. He probably at the least has more developed thigh muscles.....but that is just extra effort on his part. He was a very good athlete on the old standard F/G legs when he played Rugby.