Yes, USB cables provide with noticeable sound differences. I haven't had the pleasure to listen to Frank's made USB cables, but I did make a couple myself from his wires and they sound awesome.
The resolution of your DAC/USB interface are very important to how much of a difference you will hear. The more resolving, the bigger of a difference you will hear from everything upstream in your chain, including USB cables. That said, and if it comes to this I would prioritize the hardware first, then the cables.