Basically there are only two actual, removable/replaceable fuses in the GS/GSA, these protect the bulk of the wiring from going up in flames if anything goes seriously wrong.
The wiring to the power socket comes from one of the main control units spread about the bike, and like most of the other circuits within the loom that come from this and other control units on the bike it's got a monitor system on it that can tell how much current is being drawn by that circuit.
If the current being drawn exceeds a preset allowed amount, which can be different depending on what it is expected to be powering, the control unit says to itself " I think there's something wrong with that circuit, in order to avoid damaging myself I'll cut all the power to that circuit until I'm turned off, I'll flag that there has been a problem to the boss (fault code) and if, when I'm turned back on again, I can still detect a fault, I'll turn off all the current to that circuit again, and flag it up to the boss again"
The circuit to the power socket will go dead if you put too much drain on it. If you have socket connected directly to the battery, the control units have no sight of it so they don't have a say in what goes on. You will however have to fit a fuse to protect the wiring to this socket from going up in flames when whatever you have connected to this socket shorts out or goes faulty.
