I will pass a copy of the thread to Brian Walker at the Blackthorn Centre for his comments. This will take a few days as he is away at the moment. Personally I know nothing about the developer, I merely look after the web site.
I do know that he and the late Barry Thornton carried out a considerable amount of research into the developer. I do know version that they use at the Blackthorn is modified from the original and they did debate whether to use the Pyrocat-HD name as it differs quite a bit.