You may want to consider mqtt-based devices like tasmota or shelly, if you prefer off-the-shelf products.
I have a few dozen stock shellies in my apt., all controlled via mqtt. All of them are disconnected from the internet. Works well.
I have a few dozen stock shellies in my apt., all controlled via mqtt. All of them are disconnected from the internet. Works well.
The problem is that 2.4GHz is noisy as fuck, regardless of who’s making the noise or how. ZWave is only better because they use 900MHz.
I do think the suggestion of switching to MQTT nicely illustrates the problem though; even relatively technically inclined people frequently have absolutely no idea how their iot devices work.