I think the OP is using location not as a metric for packet routing or anything else related to the networking aspect, but as an additional piece of information that applications running on the mesh network can make use of.
Even if he is not talking about network, the example he used in github is flawed, of "auto connected devices, based on distance", maybe in US reality, where you have big houses, but ceratinly not in a real world scenario, with thousand of small apartments with everything near. The solution already exists and is not hard. try to register an airtag, or setup a new iphone with the old one and you will se the process is painless, and there is no 3d location involved.
The first example used was "auto configure the device, based on the room". 3D location helps with this, even if the only configuration is automatic labeling of the device, eg. "Kitchen Light 3".