Do you want to save money? Create a group in the discord. Once a month, buy a subscription on patreon, and upload it. Bob will ban the one who posted the release. Another one next month. It's just that someone will need to buy a subscription again...I think you get the idea. That's how I read the book. The guys buy the chapter once a month, one at a time. Voila, feel like a pirate,)
Everything is much simpler.
Bob won't ban anyone if you do everything wisely.
Why does he reveal who leaked the game?
Because whoever did this puts here, or in another place, a link to the game that Bob gave.
Using this link, he identifies.
You need to download the game, upload it to another file sharing site, Google Drive, Mega, it doesn't matter.
Create a left account on this site and leave a link to the game.
Not the link that Bob gave, but his own.
Voila! Believe me, he'll not find you out!
I don't think he's preparing a separate version of the game, with an ID, for each participant.
But you are afraid, the cowardly people have gone.
That's why the game hasn't been leaked yet.