I use a great deal of soybean wax in some soaps, which isn't SA by any stretch but is 87% stearic fatty acid and 11% palmitic (what the other 2% is, I don't know).
So this may be helpful to you, but please ignore me if not. You may also mutter "idiot" as you close the thread, but please don't tell me you did so.
Of course, it has a very high melt point (about 120) and can't be soaped at room temp. It accelerates, but less than you might think it would even soaping at 130+.
While it produces a rock hard bar in and of itself, lather is extremely spare. It does seem to sustain lather pretty well in other oils when used at 10% of the recipe, however.
Used at 15% or over, the bar starts to look waxy. Sometimes, that's an advantage. The bar in the shower has 15% soy wax in it, produces good lather (the remainder is mostly olive with normal levels of coconut, plus a lot of honey and sodium lactate), has a shiny look to it, and is lasting forever.
I made a 40% soy wax bar with mostly coconut and some palm as the remainder for use as a pot-scrubber bar. The soy seriously extends the lifespan of the bars which would otherwise be short, but does reduce the lather. They still work beautifully, they set up fast and hard, and in that case, the waxy look actually works well. I used red mica to give them a little depth and the waxy translucency works perfectly with that.