Were you able to figure out if these can be used in any useful way? I am wondering if these can be used as ethernet backhaul for mesh routers. Did you ever try plugging in an ethernet cable from your wifi router into a jack, and then a 2nd ethernet cable from a different jack to 2nd router/device?
I'm wondering if these jacks are internally connected in a way where the following setup will work to transmit a local network internally in the house: Fiber cable -> HKT modem -> Ethernet cable -> Wifi router -> Ethernet cable -> Wall jack ---different room--- Wall jack -> Ethernet cable -> Wifi router/desktop.