@JHickey These two posts may help as well with explaining what’s happening with the geometry of each piece. I use different software, but the steps are similar (and also would work in CC). The above shows using an “inside offset” to get the plug size right, I did a two pass with different starting depth . Different ways of getting at the same thing depending on the software and workflow you have. The drawings in these may help you understand what you’re trying to accomplish, regardless of the method you use to get there.
Hope these help - once I figured out inlays, I had a lot of fun making all kinds of things.
