OK, so there was another error here that neither you or I noticed before: send to V - I believe I originally had in mind send k + x to V, with k random (something like that). Point being you can send x in a blinded form but it's useless unless V can verify that what was blinded was the right x.
https://github.com/AdamISZ/from0k2bp/blob/7b3c6dbe121c5fd8eaad5d018c39c4b2aff0bbe7/from0k2bp.tex#L1018
Source: https://github.com/AdamISZ/from0k2bp/pull/11#discussion_r433859927