Nice work, easy enough to cut. Bowties are not seen very often as a joinery choice. How did you old the corners on the Shapeoko so the wood did not interfere with the gantry? Did you cut each 1/2 side individually? I guess the dowels are for purely aesthetic reasons as it is placed directly in the joint. Are the dowels going through to the other side? A dowel on each side, in the middle of the wide part of the bow, would also work well to hold the bowtie in place.
Can you share your Carbon Create file too?