This is amazing if it works. Saying there is no counterparty risk isn't correct though. Abra is the counterparty, and you are relying on them to make good with their hedges.
Hopefully tagging this comment will get your post included in the tribe posts.
Once the smart contract is open Abra put it's BTC already in. When they fail to hedge properly they will lose money and not you. The biggest risk I think is the oracle. When the oracle fails to input properly you could get a wrong payout.