Oleg's scheme is also inappropriate because it gives no ability to the blindsigner to check what he is signing. (And if you give him enough information to verify this, he'll have enough information to sign anything he wants, so again you fail to have a threshold consent scheme.)
Sure. Blinded content to be signed introduces a risk. Imho, Oleg's scheme can be useful if you know the signers and can communicate with them on a second channel (bitmessage, ...) in order to confirm your request for a signature and to "validate" (at least weakly) the content to be signed.
Another point : The scheme is asymmetric by design (coins owned by 1 user and secured by n signers). Don't know if it matches with OP's needs.