"But the exit down to the S Fork Kings? That was an overgrown bushwhack 40 years ago. I can't imagine what it is like today. It may be possible to parallel the old route above the willows and manzanita on the north side of the creek, but haven't seen (ever) anyone write about following that route."
HI Steven - By chance, I ran across a guy who had just come down Cartridge Pass and up the South Fork Kings River on the north side when I was going in over Taboose Pass last month. There is a faint use trail that saves most of the bushwhacking, but you have to negotiate 3 ~200 yard talus fields along the way that are inconvenient but no big deal. He said the main problem was figuring out which of the numerous tracks down thru the forest duff was the correct trail. He ended up concluding it didn't much matter, just pick one and go for it. He did say, however, that it was really steep. I hope to find out for myself in early September.