Many designers do not think boutique parts sound different or better. Many big names that I won't mention here think all wire, fuses, capacitors, resistors etc... that meet spec will sound virtually the same. They are wrong. Just because they are talented designers does not mean they were or are opened minded enough to test all manner of boutique parts in their circuits and relentlessly fine tune and learn.
I have had several designers tell me upgrading parts in their design would not improve the sound. Well, after prolonged and disciplined testing of "boutique" part upgrades I knew first hand the real answer. Yes, better quality parts often improve the sound in a given circuit. I assume fuses would be no different. Heck a couple of resistors make a difference, it all makes a difference.