I think you can free hand embroider on any machine.
On my mom's 1940's Kenmore, we put the stitch length on zero and released the tension from the tension bar and you could sew in any direction. We didn't add a darning foot, we just removed the foot and stitched.
On my old Brother VX, which is 25 years old, you put the stitch length on zero and put a plate over the feed dogs (the plate came with the machine), add a darning foot and you can embroider or free motion.