all things being equal
weight, surface, etc
for arguments sake, it will a new symmetrical piece with 2000 OBB finish
layout 1 55x5x50 - which puts the pin in my middle finger

layout 2 - 75x5x25 - pin above ring finger

how much added length can i expect to see from #2
on a normal THS pattern
1' or 2' or?

im a bit confused by this, wont a higher pin give additional length?
i do understand the quicker response to friction part of the layout

Will also depend on the balls core and how much higher the pin is in one layout vs the other. As mentioned the affects may be minimal to none. If it has a scoop core even less lol.

The pin to pap is the more important factor along with ball surface. Also as mentioned the drill angle on symmetric balls means nothing other then where the cg may end up.

I've seen Mo and others give layout suggestions that puts the pin in the fingers and they suggest moving it up or down enough to drill safely or just drill it out.

i had thought the drill angle dictated length
this current layout is 55 degrees and pin in middle finger
the new layout would be 75 degrees and the pin approx 1.5 - 1.75" above ring finger

i know i can adjust the surface to create a bit more length if need be, im just focusing on the difference in the layouts.
this is one fo those pieces, for me, that i would want to have more than 1 of in my bag.

Quit believing their is some magic drill angle or voodoo
The pin to PAP distance dictates the potential amount of flare
Surface dictates how where & when the bowling ball slows down and then the flare effects the reaction

Well said.

i had thought the drill angle dictated length

Correct, the drill angle after drilling does affect the length.  But for a symmetrical ball, after drilling, the psa will always be near the thumb hole so both drill angles will be the same (the angle between the psa, the pin, and the PAP) .  For asymmetric balls the psa after drilling stays very near where it was before drilling, so the post drilling angle is the same as when it was laid out.  --  JohnP

For those that would like to see an image of how much the drilling angle changes when a gradient line x hole is added and spun on a DeTerminator.  Symmetrical AMF Bullwhip SE 14 lb. 2.54 .051 PSA in thumb P2 then added PSA right of thumb changes drilling angle from 80* to 63* VAL angle stays the same.

Quote

i had thought the drill angle dictated length

Correct, the drill angle after drilling does affect the length.  But for a symmetrical ball, after drilling, the psa will always be near the thumb hole so both drill angles will be the same (the angle between the psa, the pin, and the PAP) .  For asymmetric balls the psa after drilling stays very near where it was before drilling, so the post drilling angle is the same as when it was laid out.  --  JohnP

Drill angle does not "DICTATE" length. It never did.
It is one potential factor in drilling that can affect length to some degree.
The pin-PAP distance also affects length.
Surface has a much greater effect on length.
The bowler's delivery has a large effect on length.
The oil amount AND the friction of the lane surface also affects length.
Drill angle is pretty far down the list of factors having a significant effect on ball length.