@Carl it's a hole in the line up.  I have bought into the ecosystem and would like to avoid other brands and other apps.  3 way dimmer switch is a must. 

@Carl 

Do you still need beta testers?

Hear hear on the 3-way with Dimmer. Would love to stay in once ecosystem with my smart plugs n switches.

@echo954 There is a way that will work majority of the time(haven't tested when internet is down).  You use smart actions in the app.  Wire the HS220 dimmer to the light only and in the other switch outlets use an HS200 that doesn't wire to the load at all just to power it.  IN the app create a smart action to turn Dimmer switch on when it is pressed or the group you create.  Then on the dimmer switch add a smart action to toggle the other switch.  It works fine for me with one HS220 and one HS200.

@klein103103 Great way to get around it, thanks for adding it here. Ridiculous this is what has to be done when this thread goes back 2 years. 

@damonluvisi If you do note that you can only have 3 smart triggers so you can only do this with one dimmer.  If you have two like me then you set the dummy switch to to toggle the other one.  It works but in some cases you have to hit the light switch twice to get it to change.  So that gives you 3 if you don't mind double clicking twice.  Works fine with voice controls though.

@klein103103 

I posted wiring instructions and diagrams for this a while back in the thread.  You can also get around having to press the dummy switch twice by making a smart action for the primary switch to toggle the dummy switch (i.e. two smart actions: dummy->primary and primary->dummy).  That way the dummy switch keeps the same state as the primary switch.  

(Edit: here's the post with the wiring diagram if anyone wants it: https://community.tp-link.com/us/home/forum/topic/157607?replyId=409664)

@Relayer1956 you can do 4 way on/off with a regular non smart switch in between 2 Kasa 3 way switches.