Whittler and A.S.: Thanks you both! :)
GMC: "Why do you believe one nocking point is better on shorter bows?..."
Great question and I'm sorry to answer with a one word response but here it is...
"RESULTS"
Now that said?..I could render my knowledge based speculation as follows...(translation: "what I think I know")...
There are several shortcomings of shorter bows than can present some amplified challenges as opposed to the tuning and shooting of longer bows and they are...
1: The limb tips of a shorter bow travel a greater distance than those of a longer bow when drawn and of course loosed as the limbs of a shorter bow will tend to close more when drawn and as a result?...this leads to....
2: A more acute string angle at full draw.
Note: Now #2 above really has an effect on those of us that shoot 3-Under because while the string tends to pass through the arrows nock rather squarely when shooting split-finger?...the string passes through the arrows nock at an angle with a 3-Under string purchase which has the effect of forcing the arrows nock downward on the string when loosed (Ad: Beiter actually makes Asymmetrical nocks to compensate for this but are like $2 ea,) and when the arrows nock position is restrained on the string by a 2nd locator?...the nock has nowhere to go which in the case of shooting longer bows split-finger is a good thing?...isn't for those of use shooting shorter, single piece or otherwise non- adjustable bows 3-Under and here's why...
3. Limb Timing Anomalies: Shorter bows are less tolerant of and more sensitive to things like variances in string finger position/pressure and/or grip position/pressure both of which can and do have an effect on the limbs closure timing of each and every shot so?...
For the short bow shooter shooting 3-Under?..I for one find that using a single nocking point allows the arrow a bit of latitude to find it's own center on the string (so to speak) resulting in a greater level of shot-to-shot forgiveness with one single nocking point that is set a touch to the high side which also allows for greater fletching clearance, less feather wear and smaller gaps for those who are conscious and subconscious of such.
Wait, What?...I thought I said I had a one word answer! LOL!
"Results" ;)