I really like the footbox idea on your neutron hammock. The Snipe footbox, which is from Knotty's idea, keeps the quilts inside, but effectively narrows the width of the hammock to do so. Whereas your footbox adds material, like Warbonnet's BB.
The big advantage with your neutron mod is that you can do it on both sides of the hammock, and due to the shock cord, can still enter and exit from either side without ripping the hammock! IMHO, this is real step forward in hammock design!
I haven't noticed a narrowing effect .. the snipe is 60'' wide and with the shock cord it still has the ability to extend to the maximum width .. the shock cord also allows one in ingress/egress without straining the hammock .. it does effectively take the floppy sides away from the gathered end style .. with the Snipe being 11 foot long this might be the reason .. on a shorter hammock the narrowing effect just might be incurred .. not having any experience in anything other then the Snipe with this design feature, I can only attest to the lack of narrowing effect to this hammock ..you wanna' feel narrow .. I'll loan you my Clark UL ..
"The wise man questions others wisdom because he questions his own, the foolish man because it is different from his own." Leo Stein