Yes, I think it's really important to do blind tests with gear and libraries. I often catch myself letting my own confirmation biases influence how I perceive and choose gear especially...Great idea! I didn't have the best listening conditions, but still scored 7 out of 10. What a brilliant way to demonstrate the realism of Signature Grand.
Recently, I tried something similar myself. I let seven of my favorite piano libraries record the same excerpt, randomized them and made a quiz for myself. I correctly identified them all except two. But it was surprisingly easy.