FWIW, I independently debugged this (before I saw this report) in my own NSIS 3.10 based installer, and the specific problem with relaunching on ARM64 is the fact that the code is overwriting the IMAGE_FILE_LARGE_ADDRESS_AWARE flag on the new binary (which was present in the original NsExec.dll). If you enable loader snaps on the temporary binary using gflags.exe, you will see the following: 0db8:41ec @ 495392140 - _LdrpInitialize - ERROR: Process initialization failed with status 0xc0000017 0db8:41ec...
BACKPORT: Input: xpad - fix oops when attaching...
BACKPORT: Input: xpad - validate USB endpoint c...