I assume someone else has suggested this, or you already considered it.
But I'd like add a "please" for this feature next time you decide to fiddle with the seed swap system.
When we view our wishlist, it would be great if we could have second checkbox like the "Exclude zero-quantity items".
"Exclude items I already have dibbs on".
Then we could scroll down our wish-list and only see the items we still might request.
Also - using the swap system for DnD's swap? It is still great! And I think it would scale up OK to larger swaps.
I hope it becomes a well-known "draw" for ATP, and attracts new members who have not yet been gardening so long as to already have all the seeds they ever wanted.