Not had one of those fail yet Andrew.
Fuses in the negative lead were useful for those occasions where the installer put the lead to the battery negative. Starting the engine would produce a decent current through the coax and the negative lead. Usually the PCB foil in the parh evaporated. Unless there was a fuse.
Installing a second battery with auto-isolation allows connection to the battery with only one fuse.
I’m unclear how Andy vapourised his FT817 on a summit. Any explanation Andy?
73
Ron
VK3AFW