Alternative signal: Bitcoin. If the engagement ends poorly, the Bitcoin can be un-earmarked and so the entire value can be salvaged. Many other obvious pros as well.
Even with moissanite, the ring still has inherent value, thus subjecting the wearer to risk of loss or theft. By using a pointer to value (e.g. a Bitcoin address), one can still show off but not worry about storm drains or muggings.
http://thebtcring.com/