FWIW No speaker load ever blew the fuses in my experience.

Nor in mine, but that counts for naught as I've never had speaker fuses.

However, I've had sufficient mains fuses blow on me for no apparent
reason to believe that fuse wire tends to evaporate over time (like a
tungsten light-bulb filament, but slower).

I'm particularly worried about this effect in the case of the fitted
fridge/freezer that the builder installed in our new house - the 13A
plug is somewhere behind the fitted units, so if that fuse ever
evaporates then we'll have to dismantle the kitchen to get at the plug.

--
Steve Swift
http://www.swiftys.org.uk/swifty.html
http://www.ringers.org.uk