No Neutral wire - use with halogen transformer?

We have a new home that apparently has no neutral wires - many of the switches are like diagram below (with or without dimmer). Want to install Sonos Zigbee switches that do not use neutral. It will pull some of the required current to function from the load line, which in this case is a Jung transformer (Toroidal transformer). This means the transformer (if this works at all) will always run a small current. I don’t necessarily like this for safety sake. Note the transformer drive LEDs instead of halogens. I could just get a zigbee-based LED driver and bypass building in the switches. But this would mean there is no manual option available anymore.