Another beneficiary of @lewis.heidrick 's kindness here.
I was hoping to be able to stash my hub on a shelf inside my closed rack. Just got back the hub he upgraded and I am now using the dual antenna mount (which he found for me to buy on Amazon...more kindness).
All but 3 of my 39 Z-Wave devices are now directly connected.
Add my thanks to the others given to Lewis for sharing his knowledge and skill--Thanks!