@Jack139 - if you can wait a few months Kasa has announced release of a 3-way dimmer, expected to be available around the summer I believe 

For what you propose - You will not have true 3-way switching because the dimmer switch only has a single input and a single output. 

But you can set them up in a master-slave arrangement in your automations. 

At the line end, this becomes a 'dummy' switch (output not connected to anything - you can actually use an HS200 - don't even need a 3-way switch) and you connect the line input at that box through one of the traveller wires, which becomes your line input at the dimmer switch which should be at the load end. The other Traveler is isolated at both ends. 

Then you link them in automation so if one is off, the other is off and vice-versa.