There’s something gnawing at me about all that.
There’s bugger all silhouette at night most of the time in true jungle. Or even heavy to medium scrub.
Usually infantry and even special ops go into night harbours in jungle, because it’s too unsafe to move.
The few who might move around still don’t need headbands to break up virtually non-existent silhouettes. Even if they needed to break up a silhouette, a giggle hat with a bit of shrubbery would be more useful, which is what the the VC and PAVN used occasionally.
I’ve done exercises on reasonably moonlit nights in just moderate scrub where you could be within a few yards of either emplaced or mobile troops with full gear who used the land for concealment and who wouldn’t have been any better off with headbands etc.
There may be some utility to these things, as there are to sunglasses for aviators, but that doesn’t mean that the particular style is what is required, as with the style of sunglasses known as aviator sunglasses from the WWII pattern when they fail just about every current requirement. But they still look good, which may be why I still wear them.