So I finished this little beauty off the other day, and am quite happy with it. No, it won't be up for sale, just thought I'd put it out there as something that can be done (and like everything else I have ever made, you are all very encouraged to copy it at will).
The main reason I'm putting it up here is that I have discovered a couple of things that help stabilize this puzzle design quite a bit. First, the two internal springs used for the "click" device need to be beefed up. How this helps is a bit of a mystery to me, but it makes the overall motion of the puzzle substantially better. I suspect it has to do with the fact that since the tolerances in the underlying puck are so large, the stronger springs compensate for this better than the stock ones.
Second, and this plays into the first item, having the offset vertical cut "land" on a clicked-in spot like I have done here also stabilized the whole thing quite a bit as well.
So what I'm saying is that for anyone else out there making / planning on making a puck-cube variant of most any sort, I'd highly recommend using the above 2 points, as they have quite a large positive impact on the end result.