Proof of State coin is not a decentralized currency.
This sentence is wrong in so many ways.
It's insufficiently specific, but existing examples which require developer controlled block signing or closed source software don't really pass a sanity check as decentralized tools though they're often marketed as such.
You may find this enlightening:
https://download.wpsoftware.net/bitcoin/pos.pdfAgreed. But there are also examples which don't require dev controlled block signing, and which are open source.
Can you try to give a real world example of how to perform 'costless simulation' in practice against a PoS currency? It sounds easy in theory, but I've never seen someone perform it in practice.