I have a few hideous items stuck in my collections folder forever from those crates. I'd LOVE if I could delete them. I'm betting the only reason ZOS doesn't want us to is because they don't want to deal with people who delete an item, then change their mind later and want it back. They need to just post a disclaimer when you go to delete it that says "Deleting this is permanent. We cannot bring back deleted items from the collections menu."
Those Ashlander costumes are vile. They look terrible on every one of my character except for one ... my only Argonian. They actually look OK on him.I agree that turning them into gems would be really usefull. There are so many items in the new crate season (Ashlander costumes and some random pets/mounts) that I didn't buy when they were in the crown store (because they are ugly IMO), that have returned and started fulling up my collections menu.