Anyway, I am not likely to go against the industry standard and would prefer to use wood as I am used to it and can source it locally and relatively cheaply. (I have a contact who has a shed full of old wooden last blanks).
Finally, in regard to using 3rd parties. I have gone down this route many times in the past and unfortunately don't get the results I need. I have ordered lasts from the UK, India and China, as well as from the old company now closed in Australia and they all have problems. I send them my measurements and all appropriate data and the lasts don't fit the client. In one case I took the client in for a 3D scan of their feet and had the lasts made from that scan at considerable expense and they still didn't fit.