Deleting Trophies
Welcome to Anet’s inconsistency. Some items prompt to be destroyed while other, that are of no value still, prefer you type in the full (no matter the length) item name as it appears. I find this very annoying in general, but you can always use a chat link and cut and paste into the deletion box. So if a trophy says only valid as part of a collection, then feel free to delete.
Thanks for the fyi