I too would like to voice my request to implement managed access for the 4G LTE Network Extender. I recently purchased the extender to help with getting a better signal in my apartment. While I do not mind other customers using the extender, I do have an issue with my phone not having a priority on it.
I do want to note that you can control the transmit power for the device from the web portal. I have mine set at 20% (I have a small studio.) At this time of writing I am the only one connected to it. So that could be a way to limit others from connecting to it.