Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
I don't know how to check this but it seems to do the redirection when I change the permalink structure.
Yes it does. For a long time I could not find the answer too which made worry about changing. One day I just did it and checked. The Firefox AddOn Live-Headers shows it very clearly.
Required, but never shown