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There's two noteworthy things about this photo.

 The first is that the trooper on the left is no young man. Why would he be there? I suspect he is a surgeon, and that this is a photo of three of the Regiment's medical men. That leads me to the second point. I suspect that the trooper on the right may is Dr. Emmett Spicer, who would jump, and die, in poignant circumstances, on the first day of the Corregidor operation.  My identification is tentative at best, from photos, he died before I was born.

Col. Kline, who knew Spicer well,  and regarded him as a close friend, has doubts.

 See another photo...

I'll move on to something less controversial.

The main problem with the camouflage uniform was not one of functionality, for it was better cut and designed for troops than many of the others, such as the herringbone twill one which was pretty much de facto lightweight standard.

Nor was it availability, as it was offered to a number of units.

The main problem, exclusively in the ETO,  was that the camo pattern chosen was too similar to Waffen SS patterns, which caused the troops to be identified as "enemy", especially if they used the matching camouflage helmet covers."

This was not a problem in the SWPA, which probably received stocks originally intended for the ETO.

Nonetheless it's use was limited and it was not continued. By the time of Noemfoor, Mindoro and Corregidor, it disappeared from use by the 503d.