I can only attest to the use of Hifi Tuning Supreme fuses (not lesser iterations) sound in my DAC and transport. I will be installing one in my Classe' Delta 2200 amplifier over the weekend and others will be present to assess. If it fails to impress me, I have a paid return box and it will go back to Berlin.
I have little doubt that some designers of equipment have so dialed in their creations that changing fuses may fail to render an improvement or even harm the sound. Hifi tuning fuses can be found standard in some Lamm equipment and I'm sure they were selected from among many for a particular reason. System synergy could also be at work. Just as a 6922 tube is preferred by one person in one system but not in another system, it doesn't mean the 6922 doesn't work magic in some applications. FWIW.
BTW, spending money on music is always a good idea.