>>38064910Hacking your 3ds is extremely easy, takes almost no time to perform, and has very minimal risk right now. You should do it simply to back up your saves if for no other reason.
Like I mentioned, GF checks are not comprehensive. They haven't written tests for certain obscure possibilities. The devs behind PKHex have been at this for years and have built in some super obscure checks and are still continuing to add even more. One example is gen 4 and 5 pokemon PIDs. For those pokemon, the PID is calculated using a complicated combination of IVs, TID, and SID and in gen 5, time of the day, frame numbers of the animation, etc. Gen 6 and up abandoned this needlessly complicated method so if you add a Pokemon created to originate in gen 4 but with a gen 6 style ID, it'll pass GTS checks when it shouldn't (This is the only example I have personal experience with. I've been following the dev scene a lot and I know there's one or two things from the newer gens that the GTS doesn't catch but I can't remember them)
