That's a bummer. I guess this is not really in line with the EU right-to-repair act coming into effect on July 1st and we just have to wait and see if Porsche decides to adopt that directive.
I've been lurking this forum as a guest doing pre-purchase due dilligence on a taycan, but this post prompted me to register as I share the OPs ambition to be able to do basic maintenance, service resets and diagnostics myself on my cars. For that purpose I was planning to get a PIWIS 3 clone...