Is it actually a rule in Tabula that you have to use all dice if possible? It says that it is, but it's in the section that's copy/pasted from the backgammon rules, not in the 'differences from backgammon section', which is the only place that the three dice are mentioned.

I'm asking because if it is a rule, the game is not enforcing it, unless there is something else in the rules that I'm missing. Are we supposed to use the honor system for that one?