Dear Adrian,
Your point 3 is incorrect. We do have rules on the conduct of WG letter ballots. They are in Clause 11 of the WG P&P.
In part:
Approval to forward a draft standard to the Sponsor shall require approval by a Working Group
Electronic Ballot. Abstains shall require a reason be given, and Do Not Approve votes shall
require comments on changes required to modify the vote to Approve. For a letter ballot on a
draft standard to be valid a majority of all the voting members of the Working Group must have
responded Approve, Do Not Approve, or Abstain. Comment resolution, recirculations, etc.
should be consistent with Sponsor ballot rules and 5.4.3.2 of the IEEE-SA Standards Board
Operations Manual (SASB OM).
I think your point 1 provides the best basis for providing a consistent treatment of the letter ballot.
Under such a view, the voters still submit votes with any comments they wish to make independently. The votes are counted as one vote in the ballot tally but the comments are resolved through the normal comment resolution process.
Your response to the question on whether an individual can lose their voting rights for not responding while they are subject to special measures isn't consistent with this view.
Also that response says that the voters would not be penalized for failing to respond even if they are not subject to special measures in a subsequent recirculation. The result of such a ruling could be that the ballot falls below the required response threshold as those voters start to be counted without having an obligation to vote. If the SIG is disbanded or some companies leave the SIG near the end of the initial ballot, the initial ballot might fail response threshold.
You should reconsider that Q&A response. The voters should vote as normal on letter ballot with just the tally being adjusted due to counting the votes as one.