This is going in a direction I had not expected. But a Mold swap although an interesting concept scares the @#$% out of me. I have loaned molds and had them damaged one almost to the point of being useless. But, if somehow one could figure out how to deal with damage it might work. A true mold swap would need to be carefully regulated. The only thing I can think of is an "acceptance board" where pics of mold and product be posted before it could be entered into the swap. But I think this would just be a way of causing hurt feelings.
I buy and sell a lot of molds on ebay which is my version of a swap.