Happy to help there. So all it is:
- New Game
- New Standard Game
- Yes, enable challenge mode
- Only MLB checked box
- Start Game
- Selected league MLB
- Choose LA Dodgers
- Play Mode: GM
- Start Game
- MLB>Transactions
- Offer Contract to Brandon Belt
- Ask for response > Submit offer > Auto Play until tomorrow > Eventually accepts offer
- Now here's my workaround and where I think I found a solve: if i manually remove someone from my active roster, I can then assign Belt to my roster. No irrevocable waivers. If I "ask AI to set up complete organization, lineups, etc" it places him on irrevocable waivers. So maybe it is with the logic of "ask AI..." option?
Everything else default settings