We do think it is good to have something that cues the dogs to the activity. It doesn’t necessarily need to be gear they wear. Maybe it’s a specific backpack you only use for truffle hunting. Perhaps the bell if that is the only time she wears it.
What caught my eye in the video was her being directed by the collar while one lead. While a dog who is responsive to collar tension is great for walks, it is not ideal for truffle hunting…especially when you want to build confidence.
Perhaps her leash was attached to her collar in previous videos and I missed it because she had her harness on??? Were you planning to work her on a lead attached to the collar while hunting?