Earlier this year, I noted that the Minnetonka "classic fringe" boot could be improved by replacing the laces with flat thongs, and more recently that the side openings are actually accurate for the standard Medo-Persian shoe.
Art from the period of Darius to the Alexander Sarcophagus does not indicate shoelaces run through slits or eyelets. Thus, to the best of my knowledge, the thongs should probably be just stitched around the upper edge of the shoe. So this is what I've done.
Before doing this, I also managed to pull off the heel layers. I believe that this is the maximum extent to which this particular model can be improved. I tend to work slowly, and I estimate the total time in this case to have been about six hours.
Conclusion: If you find yourself in a hurry, the earlier slit method is still okay, but otherwise what you see above is what I'm going to recommend if you don't have the skills to make shoes yourself. (Again, the hardsole version seems to have been discontinued; softsole boots can be used as-is or you can tunnel-stitch or glue a leather or rawhide hard sole to them.) The significant remaining flaws are that the soft sole wraps too high up the sides, resulting in something of a "moc toe" look, and that the forward edges of the quarter slant forward instead of backward.