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...
Have fun
Rick
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
II’ve grabbed about 6 switches and 2 dimmers. They are really good. Lots of features and feel really nice. I’ll grab a few more over time to get ride of my Wemo switches.