I used a smart relay which I built into the lamp, switch for landing lights was at front door which is never used, needed switch at base of stairs.
Hey Google turn on landing lights works well, switch still works although now extra low voltage, like any other two way switch with voice commands or phone app.
Smart switch, bulb, relay all have plus and minus points, I have Energenie smart switches, advantage it works direct with up to 3 remote controls, down side to work with phone or Nest Mini it needs a hub, and some bulbs stay on dim or have a shimmer when on, the default is off, so any power cut and lights stay off.
The smart bulb problem is every make seems to need a diffrent app to set it up, but to date all can then work with Google Home so Google Nest Mini can control them, and only one device needs the app for that bulb. Default normally on, so turn light switch off then back on, and lights work, some need a hub zigbee for example, some can use remote controls, TCP it seems does one for their bulbs, but if wall switch off, they don't work.
The relay does not matter if wall switch on or off, can't remember if it was zigbee or direct, but need room to mount it.
I have found the use of 2.4 Ghz not 5 Ghz a problem getting the router to switch to 2.4 Ghz for setting them up, found tablet worked OK to set up, phone a problem, but once setup phones worked A1.
