I'm glad that you have had no problems, but the fuses are sized for the load that they are expected to handle. If you add things to the spade that you are using, you are adding to the load on the fuse because you are adding them after the fuse (power for the addition goes through the fuse). To avoid this you can add things to the opposite side of the fuse (in effect before the fuse) and protect the added wiring with a fuse in that added wire.