Another advantage to extreme forward grip placement is that limb travel distance can be reduced, and the point in the draw the string lifts off the recurve increases. Take a good look at Border Bows riser and limb designs. ( i'm not going to go into that debate on "Lift off" that gets hairy. )
A lot of guys argue that saying, "Hey! Drawing 28" is drawing 28" regardless of where the deepest part of the grip is located." But.... If you think about it. Moving that grip forward 2", you can theoretically lower the brace height the same amount and increase the preload considerably. Of course you would still need to adjust the limb pad angle so you don't go too far.
That's where an adjustable riser comes into play. With each different limb design, you have a different working limb location, and length. Each different limb design has a sweet spot where the preload on the limbs top out as you lower the brace, then it goes down hill if you continue to lower the brace and straighten the limb out...... Once you find that sweet spot on your new design, whether it be by feel and actual testing, or using an inline scale, then I measure from the string back to the riser block and mark 7.5" as the deepest part of the grip. That determines the best forward placement for my grip.
The reason i go 7.5" is that it still gives you room for brace height adjustment without getting that brace below 7" . I don't know about you guys, but if my brace gets down below 6 3/4" i struggle with arm clearance issues. I much prefer a 7 1/4"- 7.5" brace for hunting.
Hey Flem..... What's the importance of your fulcrum point subject on how a bow performs? Just curious..... Kirk