I know I've posted this here and there, so stop me if you've heard this before (in my family, I'm known for telling the same story repeatedly because I forget whom I have and have not told). I MB about 10,000g of my fats in a huge 18 qt. container with a lid. While my hard oils are melting in my stainless steel pot, I measure out my liquid oils in my MB container; I then add the melted hard fats to the liquid oils. The container rests on a
seedling mat and keeps the entire contents of the container warm enough so that it is remains fluid. While the heavier oils do settle on the bottom (I wouldn't say they separate), because the oils are about 80-ish degrees, I can easily blend everything up right in the MB container. The last time I pulled from the MB when it was full, I measured the temperature at the surface and it was about 83 degrees. I've been using it for the last year and it is because of this mat that I feel confident MB'ing.
The mat I currently have is 20" x 20" and I can fit my MB container on it. I often have two MB containers on it at once (one for a lard recipe and the other non-lard). Because it is intended to manage getting wet and dirty, it cleans up easily and can handle any liquid that is spilled on it.
Also, the few times I've played around with soap dough, I'll put the baggie of soap dough on the seedling mat to warm it up.
One day, I want to graduate
to this warmer band, but it's so expensive and I can't see spending that when my seedling mat works just fine.