So with 0 badges, you can make your way to Blueberry Academy and start playing Indigo DIsk, including catching all the Pokemon you can encounter in there.
I am already feeling bad for
@ChaoticMeatball
who likely will do a POC for SV+DLC, that's gonna be tough pre-badge 1.
So, if you boot up a new savefile and go to Kitakami right after you start the Treasure Hunt, you will get a call from Clavell saying you can go to Blueberry Academy -
- Right after you beat Keiran the first time.
THE FIRST TIME!!!!
This makes some very wacky things possible.
Don't worry about the battle with Lacey, you can just lose to her and you will still be welcomed into the academy.
They will still say crap like "That was a good battle" man I got one shot by Minun's discharge, that's a very quick battle.
What's funnier is, you can access the Meloetta spawning spot with 0 badges.
If you want to, potentially you can encounter Meloetta within 2 hours after you start the game.
Don't ask me how to catch it with a very under-levelled team. I used Pokedolls to reach here.