The board sounds good for several different uses and I plan on making one soon. I believe I have a 4' square piece of MDF board left over from when I had to buy a 8' x 4' piece to make a headboard.
I can put a thin layer of batting on it, maybe a couple layers of Warm & Natural, and tightly cover it with some high quality muslin I have. I want a large board for ironing, specifically for squaring up blocks and larger pieces when needed.