The Foam Core/ Flexiron base was a success from a functionality standpoint. However, the time it takes to cut the flex iron into pieces and stick them on the board is not insignificant. The obvious alternative is to simply use a ferrous sheet metal. Hypothetically, the sheet metal can be hung on the wall as-is – saving hours of time.
I worked a little with a 24 gauge steel sheet a few weeks ago, which I found to be too heavy to comfortably hang on a wall without using some sort of wall anchors or a stud. I was able to find 26 gauge galvanized steel which is a) cooler looking and b) maybe 30% lighter.
I bought several e 24×24 squares (same as the foam core design) and hung them on the wall. I had the corners rounded and 8 holes punched into each square. Hanging them on the wall was a bit trickier – but doable. I made sure I put the first square up exactly where I wanted – taking care to keep it level. Then I was able to use that squares as an anchor of sorts when hanging the others. I used 4-6 nails in each square and 72 hours later, they are still hanging tough on my wall. I think each square weighs about 4-5 pounds.