Walker is developing a new and improved way of using the relinearisation droplet, but the existing approach is working pretty darn well for those of use who have been using it since it was released by Roy last year.
Or you could create your own QTR curve from scratch, using the standard QTR documentation, or the service that Richard is offering. However strictly speaking this won't be a Piezography curve. How much better or worse or simply different would this be to a custom or relinearised Piezography curve? I suspect that everyone one here will have a different answer to this question. IJM will claim that Piezography is a system, and their particular style of curves are part of that system and part of the style of print that it generates.