I have always trusted that if I cranked the limbs all the way down and backed off the same that the tiller would be the same.
Never trust anything. Check it all. I about had a cat when I saw Mathews recommending that practice, and it' s why I saw a lot of Mathews shooters shooting with a nockset a half inch or so UNDER square.
Tiller that' s out won' t do much to your accuracy. Bernie Pellerite proved that using a shooting machine. But the bow won' t feel right when you draw, and it can make the bow harder to hold on target.
I like my tiller set so that I can hold a pin on target and it will stay there all the way through the draw and anchor, rather than one limb pulling the bow up or down as it' s drawn. Even if you don' t do that test, you can feel the pressure shift in your bowhand as you draw, and that' s something that really bugs me. And one limb recovering to brace before the other one can cause the bow to recoil up or down, depending on which on recovers first.
If the limbs come back the same, then they' ll spend their energy the same on the shot.