Examples for Kant were his a priori categories, such as space, time and number, which allow us to make sense out of any sort of experience. Other philosophers have made parallel distinctions. All that hair-splitting seems overwrought. I use the term to emphasize the difficulty of discriminating and identifying transcendental consciousness. So it doesn't seem appropriate to describe the Sensorimotor Self as transcendental.
Transcendental consciousness is definitely elusive.
I do not want to suggest that the Transcendental Self exists apart from all experience. If that were the case I would not know about it. Nor is the term intended to suggest that the Transcendental Self belongs to some other, perhaps divine realm. It is part of the human mind, right here in the human realm. Also I do not want to suggest that the Transcendental Self is somehow higher than or superior to the other two kinds of consciousness.