Right now when someone wants to get paid in stables, they need to decide which asset they want when creating the proposal. This can lead to situations where a lot of proposals request the same asset and then there are not enough tokens of the asset available. It would be better to request getting paid in a category of stables, like the category USD*. On payout the treasury would then try to use all available assets of the category to pay for the request.

CC @muharem