These were terrible experiments and often done without any care to the individual. He may have had some ideas that were worth pursuing but he would have been aware that the way he did the expts was completely inhumane. Fortunately now we have proper regulations in place to allow good ethical expts to be done and all human participants have a right to volunteer and to drop out at their will.
The man was as warped and evil a monster as the human race has ever produced. The end can NEVER justify the barbaric means he used to obtain his results. His work was in no way scientific and he was no scientist. He had no hypotheses based on evidence and systematic observation for a start. That’s a fall at the first hurdle of scientific research in my book. All he used was a warped and twisted imagination.
I haven’t come across the evidence for his work being used subsequently and have great difficulty believing or understanding that any scientists of the time were so crass as to follow it up. I would like to know the sources that inform your question.