I've been contemplating using the exploding damage dice house rule, and wondering how it works in play. Have you used it in your 5e games?
On paper, I recognize that it favors anything using the foot-jabbing d4's for damage, since they'll have higher odds of exploding. Simple weapons like daggers, clubs, slings. Spells like vicious mockery, magic missile, cloud of daggers, melf's acid arrow, spike growth, and vitrolic sphere. And there's the weird effect on certain subclasses like the Battle Master where as their superiority dice evolve from d8's > d10's > d12's, they'd actually be reducing the chances of a damage explosion due to the larger die type.