Body of Argument with Gray Will

In the errata to the revised edition, it states:

Duel of Wits

Gray Will
Extrapolating from page 254, in Power and IMS under Heroic and Supernatural Stats it seems like there should be a bonus to BoA for a character with a Gray Will.
Characters with a Gray Will get +2 to their BoA.

But in Burning Wheel Gold no mention is made of Gray Will on p 391:

Body of Argument

Once the casses have been made clear, each player tests his skill. Add any successes from the skill test tot he character’s Will exponent. This total is the body of argument for this duel.

Nor is Gray Will mentioned in the errata for Burning Wheel Gold.

So in a Duel of Wits does a character with Gray Will 4 take 4 as his starting BoA, or 6? The paragraph on p 545 of BWG implies that the character should add +2 to his BoA just as he would give his Will+2 as Ob to someone trying him of something. Nonetheless, the absence of a specific reference to Duel of Wits and Body of Argument on pp 544-547, suggests that Luke intended to leave this as an exception to the general rule.

Any ideas? How do you folks handle this in your games?

A reply from BWHQ would be especially helpful. Sorry if this question has been asked and answered already. I did do a search on the forum and came up empty.

I believe that the implication on page 545 covers the generation of a Body of Argument and the lack of an explicit callout for DoW is simply a lack of explicit callout.

Now, I don’t have my book in front of me right now (I’m at work) so I’m making the assumption that p. 545 says something along the lines of “if there are mixed-shades in a test, the darker shade is given a +2 Ob.”

Heroic and Supernatural Obstacles
- pg 545 covers it, as Cathexis speculated. (I’ve my book handy.)