When checking tiller on a stick or a tree, we either clip a carabiner or S hook to the bow string or hook the string over a peg or such. This is a different angle than when we draw the bow which has the radius of the anchor point stretched out over three fingers. How does this affect tiller and draw weight. it seems that very small adjustments can have large effects on the bow and how it performs and this would seem to fall into that category.
Is there a problem with this or am I thinking too much.
 

I place the hook where my middle finger will be.  That is where the draw is centered.  On really short bows, it might make a difference to have more realistic drawangle.  On longer bows, it does not matter enough to overcome the subjective error inherent in our visual calibration of tillering.  

It does matter greatly where you hook along the string though.  I have come to hook it at the center of the string and then balance my handle on the center of the bow.  Tiller on the tree and then fine tiller by feel and shooting.

I made up a double hook to use based on my (3) finger width for this purpose. Just my opinion here, but if you're just using a single hook to draw your bow on the board then you should draw your bow an additional inch to compensate for that squared-off effect of the three finger draw (split or three under).  

ART B

I pull from the center and tiller the bottom limb about 1/2 inch stiffer. Then I check it in front of a  mirror to make sure the bottom limb is about 1/4 inch stiffer than the top. A window at night has the same affect as a mirror for tiller checks. For some reason I never really felt comfortable pulling the bow on the tiller tree from a different angle. Jawge