i could be way off the mark here but i think pokecheck only have a way to decrypt and possibly re-encrypt user created content....i.e battle video, saves etc......forcing the 3ds to run an older update would either require a exploit to make the 3ds "think" its on an older FW....thus running the 4.5 update, or resign content signed with nintendo's private encryption key so 4.5 update could be edited so the system would think its say 9.0, so unless an exploit is found in the system or the private encryption key is found (which would mean anything could be run without needing external hacks) whatever pokegen have is nothing more that a way to mess with saves or stuff that is made for use on games, might be good for save hacking etc but that's it really