If you are having trouble finding the PDF, your search term is wrong. Search engines interpret "xnxnxnxn" as a typo. Instead, use:
: For those interested in the group theory of NxNxNcap N x cap N x cap N xnxnxnxn cube algorithms pdf nxnxn rubik cube link
Yes. The World Cube Association allows any algorithm or method as long as you do not receive outside assistance during a solve. If you are having trouble finding the PDF,
: This research paper by Erik Demaine and colleagues discusses the algorithmic structure of the xnxnxnxn cube algorithms pdf nxnxn rubik cube link
Search r/Cubers for “Big Cube Parity PDF 2024”. Updated community resource includes QR codes to video examples.