The OI can move a lot, it is s strong ball for tghe conditions you mention and the line you want to play with it. Basically, I'd go with your own guess: a high pin position above the fingers, bridge are or so. Put the CG either stacked (could become flippy, though) or a bit further away from your thumb hole to make the ball movement more even/arcy. If you want a down-and-in shot, putting the pin even above your middle finger and closer to the track might be necessary.
If you want a more rolly type of recation and less back end movement, consider a drilling with the pin below the fingers. The reaction might become more predictable and the ball react earlier.
Keep the surface in OOB condition, which is 400 grit sanded with Brusnwick high gloss polish. If it moves too much, you can try a higher grit sanding base before polish application, but I think it will not help much.
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