In the 5,000 or so replies on the mod's Nexus forum thread, I did find one person mention the gap. The mod author said there was nothing he could do about it. But seeing that other modders who create armor and clothing do not have that gap, I find that a little hard to believe... In any case, it is not going to be fixed.
I have been trying it with the NCR Ranger outfit in spite of the gap, and so far so good. I switch a lot between first and third person. I use third person for just walking around, and go into first person to shoot. When I go into iron-sights mode the gap vanishes (all you can see is the gunsight after all). So I am trying just to not look at the gap the other times.
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