The technology to convert wifi signals into the placement and identity of people is getting much better. Not by using their devices, just the waves bouncing of their bodies. (There’s nothing new to the pipeline as far as I can tell, we’re just starting to get into the accuracy ranges that make it easy/useful.)
My (also not that deep) understanding is that this took a technique that was very walk dependent, and made it robust to different walks? I suspect you’d also need to vary what and where the conductive element is, I would think. Otherwise you’re just extremely conspicuous (for being an outlier) on every readout. It’s like adding an RFID tag to yourself.
Better to pollute the signal, maybe? They’re picking up on irregularities in it already (I guess), so why not add a light scramble. Maybe it can be done below any threshold to be noticeable, and you just place a box next to your router for it to work.