I like your idea, but wonder how this is supposed to integrate with the process. After all, commenting on a consideration overlaps with voting on it. (You are voicing your opinion about it.)

I can't quite put forth reasoned arguments, but I my gut feeling is (and I hope it is somewhat obvious why) that it's strongly preferrable to have this feature restricted so the consideration nodelet can't become a sideband discussion of the node.

Maybe the comment should be an optional part of the voting procedure (as in there's a text field where you can add your quip when you vote). It would force a vote out of anyone who wants to comment, avoiding the consideration discussion stalling the actual consideration process. It would also restrict consideration comments to a single-shot opportunity for each voting monk.