Why not? Have you seen Share Z-wave dongle over IP (USB over IP using ser2net / socat ) guide? You could plug the controller into a RPi and move it to a better location and give OH access to it over the network.
I have no reason to believe that switching to a different controller will improve this.
Also, keep in mind that this map is the map of neighbors and does not necessarily reflect the paths that actual messages take. And the red arrows do not indicate connection problems. I’m not positive about this, but I believe the red arrows are showing non-reciprocal neighbors. For example, 2 is listing 1 as a neighbor but 1 does not list 2 as a neighbor.
Now I do agree, this map does not look healthy. I’m just not sure that replacing the controller would fix your problems. It might. But when I had a similar problem, I added another mains powered device a little closer to the controller to create more solid paths to the controller for the other nodes and everything started to work great.