Mesh Networking and TDoA needed

I am currently working with a client to investigate integrating RTLS into their existing industrial SCADA system. I was very close to ordering one of the MDEK1001 kits to start evaluation of the technology but came across a couple of issues that have caused me to pause a bit. Please help me resolve these issues.

First off, let me briefly describe the existing system. It utilizes a Zigbee module at each controlled/monitored node in the system. There can be up to 1000 nodes in a large deployment. All nodes are part of a Zigbee Mesh network that route data to/from the nodes to a single gateway. Several hops are required to cover the entire system.

In the current investigation, I would like to replace the Zigbee modules with DWM1000 modules. These modules would need to perform the mesh networking back to a DWM1000 equipped gateway. The DWM1000 modules would also be required to perform TDoA measurements from DWM1004C based tags, returning their measurements back to the gateway via mesh for position processing.

An alternative I am also exploring is the possibility of leaving the Zigbee modules and mesh network in place, but adding a DWM1000 to each node to perform the TDoA measurements. Then use the existing Zigbee Mesh network to transport the data to the gateway for processing. Seems silly though given the bandwidth available on the UWB radios.

My initial thought was to use DWM1001C modules for anchors (and control nodes) but it seems that they are not capable of supporting TDoA. Will there ever be a device like the DWM1001C that supports TDoA?

Also, can you confirm that Mesh Networking is not implemented on any of your current devices? I found reference to that capability being added in a past newsletter, but no sign of it actually being available. Will it ever be available, if so, when?