This is, like, so wrong.
Only the small N3DS's from JPN and EUR were ever exploitable, and those came with 8.1J sometimes. None of the N3DS XL ever had 8.1J.
Your right im in a rush the white japanese units will have 8.1-9.2 just read this thread http://gbatemp.net/threads/n3ds-xl-firmware-by-version-number.381479/