You could go to make an edit of the piano sound, and transpose each layer down to the key you need. This would only be an emergency workaround, and should be ok with only a couple of layers on piano.

It still feels silly to me that such expensive instruments are perfectly capable of having different sounds saved at different octaves at the same time, but have no direct option to save on different keys. Even if it was a feature you unlocked through a menu, it may not suit everyone.