The only problem with these is price. It turns out to be quite expensive to make only few of them. Just the cost of the PCB alone can go from 40$ a piece to 2$ depending on quantity. Hence, unless a group is formed to order them in batch, the prototype/DIY/open source approach will be the only way to go.
How would the cost compare to buying a DA or RH timer? If it is not much cheaper, is there some other advantage?