The hurricane is past us. We had 10 hours of heavy rain and some wind but never lost power.
The HiFi Tuning fuses, 6.3A T Slow blow type arrived this morning. I installed them in my mono amps this evening and turned the amps on. One amp stayed on but the other amp turned on only for a moment and shut off. Pulled the fuse and confirmed with my Ohm meter that it had blown.
Experiment is over. I've had my fill of hifi fuses. I hope I can get a refund from the vendor for these two. I already took it on the chin for the last two fuses.
The Hifi Tuning fuse in my DAC is still working fine and it sounds good. I'm not touching it.
This is audio. Sometimes we win and sometimes we lose. Not knowing isn't an option. And if anyone wants to claim confirmation bias, I'm almost certain the one amp would not have made any sound had I left the hifi fuses in place.