Okay... but you could also just, go through the routes again? I don't see the point in replaying the entire game if you're allowed to cheat until you make it to the one point in the game that's relevant to the challenge.
Well yeah but you cant get a new starter that way tho, ik its confusing cause everyone is used to battling, and even if you got a pc box of Pokemon, its gonna take time releasing the mons in the box and party, run or fly aaaalllllll the way back to route 101, get a new mon, go back to the pc, release the last mon, and possibly if you have HM fly; skip the routes and fly back to Place A, lose and repeat, and to me doing that way kills the meaning behind it, with restarting fully not only you have to recapture, but also have to grab HMs again, and as for level caps is to make the contest harder cause youre limited to the moves
Edit: for example moves that has cute categories; what i mean by limited is when you only have 1 cute move and other 3 is smart
Edit 2: as for OHKO, ohko doesnt work on the contests
Edit 3: Should look at the docs again cause it was updated a few days ago (a 2nd update)