Bob,
Your observation is correct: The original VM1 pop screen, included in the original KHE package, is a bit on the over-protective side, with moderate impact on the high frequencies. As well-designed and executed that accessory was, we opted to delete it after about fifty mics sold.
All popper stoppers currently commercially available range on a scale from fairly transparent, though detrimental to the capsule's cleanliness (and their inability to suppress some air sounds), all the way to super-efficient in the suppression of unwanted air noise, but with too much attenuation in the highs and transients.
So, all of these products affect audio, more or less.
I found a good compromise between protection and acoustic transparency in using a wooden crochet ring, minimum of 8 inches, with two planes of single layer hose/stocking material lightly tensioned across and mated to a standard mic stand thread.