@ScottMan can you please explain a little more in detail. My electrician and I are trying to understand it. Are you saying we need two dumb/sattelite (only 2 screws) switches and one master (3screws)? Are we to replace the the 4way with a dumb/satellite switch. If so, please explain a little more in detail. Thank you for your help and fguring this out. TP-Link should really fill this void out.

  @Carl Would this also work for the 3 way dimmer switches? The KS230. 

  @Blunoz are you able to get the smart actions to work without a delay? I haven't looked into it too much, but when I tried the smart actions there was a several second delay between hitting the switch and the light changing. The hardwiring is much faster - although still not instantaneous like a dumb switch. Also, this method works well when the wiring is already in the wall. I'd love to use the smart actions in other situations, but I can't stand the delay.

  @Rusalka68 - see https://community.tp-link.com/us/smart-home/forum/topic/161800?replyId=1160712

I was inspired by @PatchyFog's awesome video and set up a similar test bed to try some ideas on the 4-way with dimmer configuration. I was surprised to find a relatively easy solution. The KS230 kits come with one master and one satellite device. It's clear that the traveler 2 wire is actually powering the load, as they are wired together. So traveler 1 must be how the switches communicate with each other. Since that communication has to be bi-directional, I assumed the internal electronics on traveler 1 are likely pretty robust and would be able to handle a third switch that could set or sense that line. So, I simply added a second satellite in series with the first and everything worked - all three switches could control the dimming and I could control the circuit using the app. Here's the configuration in order:

1. line

2. master - connections out on travelers 1 and 2, as well as neutral

3. satellite 1 - travelers 1 and 2 connected to switch and output, neutral pass through

4. satellite 2 - takes travelers 1 and 2 with load connected to traveler 2, neutral passes to load

5. load

Note this is essentially replacing the 4-way with a satellite where the input/output travelers are connected together. Unfortunately, I haven't found anywhere to just buy a satellite so you need to buy a second KS230 kit just to get the extra satellite. 4-way switches normally come at a high premium, so this doesn't seem too bad. This configuration could expand to multiple switches, but I don't know what the limitations are for the internal electronics.

I wish the KS230 would work in a 4-way.

Wasted 2 hours today trying to get it to work :(

  @NevHuntre Same here, we were trying to install dimmers in the 4 way setup, but could not get it to work (had an electrician here experimenting but they could not figure it out unfortunately). 

  @DavidDoria 

I've found that the 3 Way Dimmers don't work the same way (unfortunately).  I did replace a 4 way circuit in my house with a 3 way Dimmer kit (the KS 230), but "killing" the 4 way switch.  I bypassed it like you mentioned, which worked fine.  I think the dimming capability requires and actual dimmer switch at every location (maybe just so you can dim from either place).  Using the combo 3 way smart switch with "dumb" 3 way and 4 way switches only works if they are all just "boolean" switchs (on or off).   At least that's been my experience.