Pioneer54: Curious suggestion! Would the doubling cube be used?

No. It's not used in the current Triple Gammon tournaments, so I don't see the need.

One obstacle may be the time. Dice10 takes much longer than the gammon games, so a short time control (I'd say one day, or less) might be almost essential, otherwise the whole thing could take years.

Why? Whether you play with "normal" scoring or the scoring I suggested will not affect the average game length by much. And while I have finished a number of Dice 10 games, I didn't get the impression such games take an overly long number of moves, they are certainly shorter than most Anti- or Cloning- gammon games I've played.

But you are free to not join tournaments if the move time is longer than a day. And once you're a rook, you're free to define tournaments with move times of a day or less. Don't expect me to join them though.