OK thank you.
Note that it is already possible to restrict some markets so that you can turn on/off the exchange of certain coins. You can create pairs where it’s only possible to buy or only possible to sell. You are telling me that you would like vendors to choose which coins to accept as payment for WCMP. This is currently only possible with some PHP coding, i.e. you could intercept with high priority a move action that has the wcmp tag, and throw an exception. I will see what I can do to make this vendor-friendly via the admin ui.
with regards