Only thing is, when I was embroidering, a corner of the towel got caught under the hoop, about a three-inch triangle. The stitching on this design is very intense and there was NO WAY I could pick out those stitches. I cut off the bottom of the towel along the trim, losing about five inches of towel, and used my serger and sewing machine to finish the edge. Doesn't look all that bad, but there is still the matter of the corner of the towel under part of the design.
I had meant this as a gift, but it looks like I have a pretty new towel for myself. On the plus side, the Q foot worked wonderfully even on a thick towel, even with two thicknesses of the towel where it was caught on the bottom. Looks like I can go back and revisit a design I got for a towel that I just couldn't stitch out because the towel was too thick for the R foot.
I think that these misadventures are just part of the curve of learning, not happy but not terrible either. Next time, I'll hoop differently.