I'd chop the pyra to the lowest node. Wire some movement in the new leader and just let it grow free for a long time. You can chop it back to create taper every couple years. If you are happy with shohin I'd do the same thing except put a little more movement in the new leader. Maybe let it go for 2 seasons then chop back leaving two nodes on the new leader. One will be your primary branch on the new leader. So on and so forth.
This is exactly what my plan was