Darn soap gremlins!
FWIW, maybe this could be a partial explanation for some of what you observed - there’s a limit to how much salt, bicarbonate, lye, sugar, etc. can be dissolved into a given amount of water. When the max is reached, the solution is fully “saturated”. Between the salt, bicarbonate and lye, your lye water could have been close to “saturation” and then when you added the sugar, you may have exceeded the capacity of the water to dissolve any additional solids. In general, the higher the lye concentration of your lye water, the lower the capacity to dissolve additional solids. The salt and bicarbonate add to the challenge of dissolving addition solids, relative to making the lye water with non-salty water. Then (speculation!), if the sugar was forced out of solution first (or kept out of solution) and then it melted as the temp of the lye water increased, I can imagine that it would make gloop in the lye water.
I don’t have any ideas for the lumps in the batter
Are they soft, like partially solidified fats? Or do they seem more like crystalline solids?
As for the initial size of the salt crystals, it should not matter at all once the salt is dissolved. On the other hand, it may have affected the weight of the salt you ended up adding to make the faux sea water. The coarse salt will not fill the measuring spoon as tightly as the fine salt. If measuring spoons with coarse and fine salt are both leveled, the one with the fine salt will weigh more because the salt is more tightly packed in the spoon. Unfortunately, I don’t think this helps to explain what happened in your situation because faux sea water with a lower concentration of salt would have more dissolving power relative to fully saturated sea water.
