Buying tritium at quantity at a station with large pads (if you can find one) and making trip after trip after trip to fuel an FC is tedious enough, but I can only use half of what I put aboard my ship or I strand myself until I can spend dozens of hours mining tritium out in the black. Why not let an FC refuel from the star it is orbiting, perhaps taking 24 hours or so to fully fill the fuel tank or, alternately, allow for a special kind of fuel scoop that can be fitted to a ship allowing a ship to scoop tritium that can then be transferred to the carrier?