It could be interesting to add dice and coins stack as standard game objects like the Decks that is actually supported by Vassal.
can already do that.
for example (dice), create your dice with a basic piece and add a layer with as many levels as you need sides. The layer follows a dynamic property which can grab the last value property of a hidden dice button that is invoked and rolled through a global hotkey. There is a demo here somewhere that shows all of this.
Coins could be done in a similar manner without the random dice roll