A high lye concentration is great for avoiding ash, but it can be tricky to get the soap to gel. For a palm recipe I make at 35% lye concentration with 25% palm and 20% CO, plus sugar in the recipe, I can force gel if I set my mold on a heating pad set to high, cover it with cardboard, then a towel, then a fleece blanket and then keep it warm until I can see that it gelled completely. It might take a few hours for 1000 g of oils in a thin walled, silicone lined wood loaf mold. A few weeks ago I moved a couple of small batches (500 g oils, 35% lye conc.,palm recipe, stand alone silicone loaf molds) off the heating pad and into a slightly warm oven. After about 2 hours on the heating pad, the batches were clearly gelling in the middle, so I thought they would be fine. Despite wrapping the molds in a towel to help keep the heat in, I ended up with partial gel in both batches.
Did you work at a fairly thin emulsion? I get chalky soap if the emulsion is thin and the soap doesn’t gel. Although I can force cut bars of chalky soap made at high lye concentration to gel in the oven (at 200F or higher!) and actually watch the chalkiness diminish or disappear, the final texture remains a bit grainy. You might want to pop a bar or two into the oven as an experiment. To avoid that problem I bring the emulsion to a slightly thicker consistency and make sure it gels. It took trial and error to recognize the right consistency.
Your soap design is really nice and I’m sure you were looking forward to the cut. I’m sorry it didn’t work out as planned.