Just wanted to report that I have successfully installed an Inovelli Black switch in a 3-way with a GE Aux and it works as advertised.
Took some time to figure out the wiring but other than that...
Edit: Forgot to mention, @Eric_Inovelli your documentation in the box and online are some of the best I have ever read. Easy to follow. My issue was tracing my wires and knowing which option to use... Not an Inovelli issue