I'm thinking of using two PD-6ANS switches. The load of the remote one will connect to the blue wire on the main one. The remote will just be an overpriced toggle switch with no programming features used but it will create a visually matched set of switches. Alternatively I will use some other kind of switch for the remote but it might be a smart switch of some sort to match the other main house switches.
I've installed and use a PD-6ANS with no issues at all. Wiring is rather simple: the mechanical switch does not switch anything but rather signals the 6ANS to do so.
I am not sure though that another caseta switch could play the mechanical switch role successfully as it really does not disconnect 120V entirely as a mechanical contact would. I vaguely recall although I may be wrong that in the 'off' state a PD-6ANS has high voltage on its output anyway. That may be enough for its partner not to act as you intend. Unfortunately, Lutron has not bothered to produce a real mechanical contact caseta switch (there are such of zwave persuasion).
Edited by vc1234, 28 October 2019 - 08:08 PM.