I'd like to suggest that studios may have access to a shared inventory where other teammates may purchase items donated by same studio members. My vision:
Have Misty's Atelier be a smaller button. Below the Washing Machine, have a same sized button that would function much like the others, where a pop up would occur.
The pop up window will look similar to the 9 item section where we get new goods daily. There will be an option to donate item and replace one item already in inventory. Nine items max, or the developers can choose to make it 6. Either way, this is still an option players would love to see.
Other players from the same studio (no other studio) may purchase one of these donated items by spending 10 diamonds.
For the players, this creates a team work environment and a feeling of not completely wasting our previously spent diamonds, especially where 19 diamonds were spent on re-rolling for better refinements. For the developers, this is another option to have players spend diamonds. Both players and developers benefit.