Re: If it's not luffing, it's helping?
I can't explain the theory, but I have done a lot of motorsailing up and down the Chesapeake, alone as well as in company of other boats, and can say that motorsailing increases speed and saves significantly on fuel. Also, you can motorsail much closer to the wind than you can sail. I don't think you gain by moving the traveler hard to windward, although you can prevent the sail from luffing that way, and I do it occasionally, when I'm motorsailing head-to-wind, or nearly so, in a narrow channel, where I don't have room to tack. If you have room to tack, the better choice is to approximately center the boom, or "cheat" it a little to windward, and then motorsail at an angle to the wind that produces good drive from the sails and good speed. If you tack with the wind shifts, you'll help yourself even more. Even though you will add distance by tacking back and forth, you'll gain enough in speed and fuel savings to make it worthwhile.