@Chicago_SH hello. Recently installed according to drawing. Left the 4-way switch alone and only added TP-Link 3-way switches on the other two locations. Problem is that when I flip the 4-way switch it turns off the power to one of the TP-Link switches. So I'm guessing the 4-way switch is on the end of the circuit not in the middle. Can anyone confirm if that is probably the case or something else happening?

  @Augustlion This thread is long enough that it might be time to plug my deep-dive video on this topic here again. It may help you. https://youtu.be/kMT7KUVTELo

  @xRkYqUz Yes, that's what I'm currently trying to install.  Believe me, the struggle is real!

I need to try some continuity tests, but I think this is my setup.  Between the positioning of the lights, and a 3-way at a dead end, it's driving me crazy.  If anyone has a solution to this I'd really appreciate it.

My instinct is to try the HS210's instead.

  @Ant._. I have 1 3 way replaced with a smart switch and it is working on the app. The other 3 way at the other end does not have a neutral wire. If I connect a second smart switch without the neutral connected, will it be able to tell if the light is on or off?

@Carl yes, this is exactly how I'm setting my switch configuration, with one tp-link 3 way switch at the end with the neutral wires, one regular 4 way, and one regular 3 way. I believe this will function fine. 

@board4mic 

I am trying to follow the 4 way switch hook up. So when installing the two kasa three way switch do you hook up the white common or is it left out. Looking at the diagram it is not hooked up. Any help would be great thanks

@HappyKing 

What's a laser wire?  

@Chicago_SH confirmed to work. Just followed directions, placed it in the 2 switches that have laser wires. 4 way has 2 red and 2 black.. where as 3 way has 2 black and 1 red. Went through the pairing instructions. Worked like a charm. Thanks for putting those directions.. I think TP should publish this to avoid searching. I don't know why some say it's not working ..