Their is a group of individuals forming that plan to intentionally attack POS coins.
https://bitcointalksearch.org/topic/cleanup-ill-attack-some-coins-i-owned-apexcoin-for-90-blocks-897493
And it looks like they have been successful in attacking Apexcoin with an attack.
https://chainz.cryptoid.info/apex/
Don't know if it would be a concern for ECC, but post it so you would know what they are up too.
i will be looking at this carefully. thank you.
Edit: holy shit this is great. thank you very much. this will help me a ton in many different ways. (i will also try to see if i can think of a fix for this PoS problem)