I can confirm that if the lvl 0 pokémon gains experience, it goes from lvl 0 to whichever level it was set to, but it's fainted. You have to revive them / go to a pokémon center.
I've found out that the Dream Ball legality check is apparently wrong, since now you can obtain the dream ball and use it to catch any pokémon.
Also I think relearn moves / TMs / TRs aren't updated yet, for example, Shadow Ball and Flash Cannon Aegislash and so on.
Other than that, everything else seems to work fine.