stonecoil interacts with this the worst in terms of getting counters when the creature dies, yes. the card is still capable of being 1 mana for a large number of +1/+1 counters when doing things with ravager. even with stonecoil it enables lines like casting a serpent and then eating it with ravager to get all that mana you just spent to translate to +1/+1 counters that you can now ravager onto an existing creature that turn, put on a ballista, or put on a hangarback.
I see that, but the opportunity cost is that this Ozolith is a drawn card - as opposed to just another solid threat. It requires ravager to do any kind of modular tricks, and it just seems you are more forced to put eggs in one basket to get value from this. In mid game, when you have no ravager, are you ever going to want this to be the topdeck (for a deck with minimal card draw)?