Ed,
And, (this is an observation, not a criticism) the NEC people are being very cautious in recognizing series rated combinations.
Actually this is just a turf war between the manufacturers of fuses and breakers. There is no question that a current limiting fuse can do exactly that and could protect the downstream breakers, but the breaker manufacture does not want to be in the position of saying a competitive product will protect his breaker.
Don
