You guys managed to bang out Farcry 5 and Oddessy as well as Hitman 2. They all use always online single player Denuvo anti tamper DRM's. Although Farcry 5's was quite a bit more interlaced, If the trainer does not break yours or the devs conduct code. I have faith you guy's can manage it.
Those games don't use a server..
Actually, in the demo, i am not sure if the full game has this, but you are forced into public mode from private mode in free-play mode, it is only possible to play in private mode when playing the story missions for obvious reasons.
Anything else is forced into public, which is a very bad thing in my opinion, either way, it renders the trainer prospect as impossible.