Update on the metal smelting.
It happens with any metal that didn't come in the base game (just tested to be sure after getting a bunch of them from my cauldron--which made getting them faster, I just had to set motives to static to do so!). Try to smelt it with any other metals queued for smelting after it and the Sim jumps. You can smelt them one stack at a time, but that's a little annoying. I get a script error on the Sim (Script Error: Jewel Collector), but I don't think it logs it.
I'm about to re-test reading children to sleep with actual books. That's how it glitched before, but as I said, it didn't glitch with the tablet. I can read with them normally for sure (I did it before), just can't read them to sleep or read a bedtime story. But I can with the tablet, so that may be a workaround for anyone else having the same problem.
But the only gardening issue I have is the "mycelium" issue which should go away once SN is installed. I hope. But I don't click on every plant, I just use "tend garden," so I very likely may have the issue and just haven't seen it in my gameplay. Given the issue with very specific metals (which is why most people probably haven't encountered that glitch--most metals exist in the base game--aside from the fact I was specifically playing a character who collects and sells the collectibles)I wonder if the gardening glitch also takes place due to specific plants (i.e. if any are not from the base game).