Ugh, I think I figured it out, and I feel kinda dumb lol.
JDRobert’s mention of the required white/neutral and my lack of seeing them got me thinking and researching, where I discovered that you often have to dig into the back of the box to find the bundle of neutrals spliced together under a wire nut, and introduce a jumper to draw it out for use.
Sure enough, if you look at the picture of my office switch box, you can see the bundle of them tucked in the back lower corner. This aha-moment also brought light to the fact that every GE Zwave switch I’ve purchased has come with a small jumper wire that happens to be white that should have clued me in, but didn’t.
I guess the assumption a laymen makes is that the instructions make it seem like the box “could have” some variable number of wires coming out of it, from 3-5, including a traveler and a neutral, and that the name of the game is to MATCH and connect only the ones immediately presented.
So while a lot of effort is put into warning the user to ONLY connect the traveler (red) in the event of a 3-way, there isn’t much effort placed on requiring the white to be jumped in even if not immediately present, so it’s easy to assume it’s optional as well.
To make matters worse, I still don’t even know how my other GE Zwave switches are working in other areas of the house where I have the bare/ground plugged into the Neutral terminal, but I’m assuming that’s probably REALLY wrong and possibly dangerous, so I need to go remedy those as well. There, the poor assumption I made was assuming that the GE Switch would be laid out using only corners just like a basic switch, with the only difference being one extra corner for the Traveller. I didn’t even notice the green up top.
Anyhow, hopefully this helps others, I’ll post a picture after I get the neutral jumper installed.