Noting that the purpose of a fuse is to protect the wiring between the load and power source and not the device, a 1A fuse would be sufficient to protect the 22GA wire the Bose harness comes with, however, having all four jacks being protected by the same fuse would mean that a fault in any of the jacks would cause all four to lose power. Either way is electrically safe.
The trade off is the time and material to install four fuses versus continuing to fly without LEMO power in the event of a fault in one of the jacks if a single fuse is used.
Personally, I used inline fuses for each of the four harnesses. Also, the installation instructions that came with my Bose harnesses call for 1/2A fuses; I recommend going with that size versus 1/4A fuses to prevent a spurious fuse blow.
