Medals you get via returns, are also server sided. I tried messing with them, and the game perfectly knows how many you have, and will remove levels gained from using them as well. Data chips (used to level Slugs) are device sided, but server checks put those in check, but you can mod them, then fully level your slugs, and try to plow through the stages you need to require getting them. Keep in mind, the mats you used after modding will be gone, but you will gain much more this way, but slugs will revert back to their normal level when you reboot the game. It will make the most of the limited tickets you have to run those, which seem to be server sided as well, and if not, are checked heavily by the server, and that goes for all tickets. I've yet to mess with the stage counter, as another user has informed me that when they did, and froze it, then did a return, the game kicked him back to the main screen, and says they're unable to play anymore. If I mess with this, I'll have to do it with another account.
So, unless people are able to mess with challenges to where you can always complete them, and they never go away (like Pokemon Quest as an example) I don't see much happening with this hack wise. Unless with my limited skills, and know-how, I'm wrong. There's other things for me to try, but I have a feeling they're all going to go the same way.
For anyone wanting to try this, do Fuzzy (Unknown values) Double searches in addresses 7035200-7FAC1FF, for coins, and data chips. They're normally in the 75000000-76000000 range. Could be higher.