Checked with VZW support on the Network Extender side.
The rep that I spoke with suggest that the VZW Network Extenders are not compatible with MVNO's at all. This has to do with the nature of the device and how it VPN connects direct to VZW before allowing anyone to use the device. I am under the impression that the Network Extender will only work with true VZW lines.
Bummer, a single phone line at my level of usage is not cost justifyable with Verizons current offerings. I'll keep searching for confirmation but I suspect what I want isnt going to work.