Given that I’ve had only a few experiences with soap overheating slightly and no volcanoes ever with my recipes and methods, I put almost every batch on a heating pad or in the oven (CPOP). However, I think recipe, FO and lye concentration are key factors to consider in the strategy. I typically use 35% lye concentration, and regardless of recipe, the batches (500-1200 g of fats) do not want to heat up much on their own. As a result, I’ve had more “cold soap” fails, like a weak emulsion leading to graininess in a “designed” soap, than problems with overheating. I could probably leave a batch on the counter to do its thing when it’s made with beer or an accelerating FO, but I usually stick it on a heating pad, covered with a blanket and watch it until I’m sure it‘s starting to gel. I find it easier to check on a batch that’s on a heating pad, but do the same thing if I’m using the oven.