GF...maybe I can answer your questions here....
Q1: What is the up-side to cutting a bow past center?
Answer: It gets the arrow more aligned with your bows string path which in turn gets more of the bows energy into the arrow.
Q2: Is it more tolerant of imperfect spine?
Answer: Yes...it is..but a better way to put it would be to say that the closer the arrow is aligned with the bows string path?...the less sensitive the bows preference for exacting dynamic spine values it becomes thereby leaving the archer with a greater range of tune-able spine/length/point weight options.
Q3: Do higher-spine arrows penetrate better on game?
Answer: Yes...they do...reason being is because all that flexing a low dynamic spine arrow does as it goes through it's many in flight oscillations comes at a cost...the cost being "Lost Energy"...as it takes and robs energy to make that rubbery arrow do it's hoola dance on it's way to the mark.
Q4: Is cut-past-center easier to aim with??
Answer: No...same same there provided the archer is railing their minds eye down the arrow shaft as they should and the rig is well tuned.
Q5: It's just that after being advised to build a strike plate way out to accommodate the same spine on a recurve that I use on a longbow.... Why not just cut them the same to begin with?
Answer: Longbow risers are typically far less beefy than are recurve risers...there's only so much material the Bowyer can remove from the arrow side of the longbow riser without compromising the bows structural integrity however?...
More recently we're seeing a trend where Bowyers are either adding more mass to their longbow risers and/or incorporating far stronger materials than just wood where the Longbow winds up sporting a riser with the mass of a typical recurve that's also made of stronger, denser modern materials such as Phenolic and G10 which in turn permits the Bowyer to cut his longbows riser window past center without compromising it's structural integrity.
and now I'm ready for my 2nd cup of coffee! LOL!
Good morning all! ;)