I have seen information about putting a 20 amp fuse on each of the three stator leads. Good idea? Bad idea? No difference?

This is the explanation as said in a different thread:

If the r/r is fried, as in shorting out, it will cause the stator to "burn up" from the heat it creates from making electricity. This equation, V=IR, voltage = current X resistance, can be reconfigured as V/R=I, or voltage divided by resistance = current. One equation for watts (heat) is VI, voltage times current. If the r/r is shorted, the resistance of the r/r = 0 (shorted to ground), so the current from the stator is 50 volts divided by 0. By theory, this would mean that the current being produced by the stator would be infinite. Watts, then, would be infinite, or at least hotter than the sun. The wires and insulation making up the stator would melt, thus decreasing the voltage output to nil. And there you have it, a shorted r/r kills the stator. This is why it's important to do the modification of "fusing" your stator, so that a current output of more than 15 amps will kill the fuse, as opposed to killing the stator.

Great explanation...

So, rather than 20 amp fuses, are you suggesting 15 amp fuses?

Yeah. I've heard of 20 amp fuses still not catching a shorted r/r. I'd try the 15 amp fuses first (I've got the stuff to do it, but haven't yet). Keep three 20 amp fuses handy just in case, because, I could be wrong.