In Tomiki Aikido, the first technique that you learn--shomen-ate--is the most advanced technique that you will ever learn. The first step is to learn where the most effective position is. The strongest attack against a two-legged human is a line of force perpendicular to a line drawn across the the toes (or heels, etc.) of a person.
I would not call Shomen-ate the most advanced technique - probably just the most sensible
The floating waza at the end of the 17 - those would be my choice for advanced techniques.