Yeah, I initially looked into developing something with this scheme in mind, but decided that it wouldn't suit because it was too clunky (with all the refund transactions, and DOS angles) and only supported bitcoin derivatives, whereas I wanted to offer a lot of '2.0' currencies.
TierNolan's (et al) proposal isn't tenable (especially not for trades where the game theory of profit tied to market bid/ask order book is in seconds or microseconds) until at least we can guarantee that block chains don't orphan and become probabilistically final on the order of seconds or less.
Btw, I think these requirements are only required on the altcoin chain in order to interopt with Bitcoin. Thus afaics the reason you can't implement the proposal is because the altcoins don't meet the requirements.
the decentralized P2P atomic exchange protocol.
Again the problem remains it is jammable. I offer an idea for mitigation, but it is impossible to entirely squelch it.