I'm not going to say it would be necessary, but I will say it can be beneficial.
The less finger/fingers I have on the string when I drop it, the closer to even my tiller can be, and the closer to square my nocking point can be.
Joel, when getting into this you are talking about the world of "Fine Tuning" within a reasonable tiller anyway, but here's an example for you:
A single bow with two different shooters. Both shooters have the same draw length. One shooter has fingers considerably "larger" than the other.
The shooter with the "larger" fingers may, and often does need a tiller more to the positive side, and/or a higher nocking point.
I'm cramped for time right now, so if that don't make sense to anyone, say so. I'll try to keep up with the topic, and elaborate if needed, or you can PM me.
Rick