You can have your choice of a coin-flipping Omega, or an Omega that leaves box B empty unless you would one-box no matter what.
...or an Omega that fills box B unless you would two-box no matter what.
Indeed, you could have any mapping from pairs of (probability distributions over) actions to box-states, where the first element of the pair is what you would do if you saw a filled box B, and the second element is what you would do if you saw an empty box B. But I'm trying to preserve the spirit of the original Newcomb.
Here's an edited version of a puzzle from the book "Chuck Klosterman four" by Chuck Klosterman.
When should you punish someone for a crime they will commit in the future? Discuss.