My thought would be, if you did that it would depend on what items you are trying to power...if you were going to use the outlet for powering a
portable air compressor then the fuse rating would be higher than if you were going to power a GPS
The circuit under there is only designed for 5 Amps max no matter how many plugs or jacks you wire to it. Upping the fuse size will put your wiring in danger of a meltdown. It really depends on what you're going to run in them as to whether you will overload the circuit or not.
I have 3 sockets on that circuit, with a double USB plugged into one of them. I have my cell phone charger and my 7" GPS in the USB socket, and another GPS in another socket, 1 socket is open. This is my set up most of the time. I have a 5 amp fuse and it has never burned out.