running 4-of-2 definitely removes the service dependency.

you highlighted exactly the "bug" i wanted to patch though: the collusion risk. if beneficiary A and B have a beer together, you get rugged.

the "live service" here acts purely as a time-lock. beneficiaries can't collude to rob you today because the 3rd shard isn't released until the dead man's switch actually triggers. it protects you from your own friends.