I would just place the pin on my negative axis point (NAP)
That would basically be the same as drilling it pin axis, which is the most stable position you can put a ball in.
Like this

    o o

P    C

     O

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I know a guy who has his plastic ball drilled on the opposite side of the pin.  It doesn't matter, put 3 holes in it and throw it.

If you are wanting it to go straight, just drill it over the label.

  I have a columbia white dot with the same specs as your tuff.  I drilled it over the cg (label) just to keep it legal.  I use it for spares, but it does go straighter than my old, plastic, A.M.F. boogie ball.  They should be close, but they really aren't.

  On real dry, the boogie gets down the lane and turns on the backends, while the w.d. doesn't turn.  It seems to roll earlier than the boogie and have less backends.  Plastic won't backend much on our condition here anyway, but the boogie definitely does a bit more.

  They are both plastic and drilled over the label.  The white dot having the pin on the bottom is the only visual difference I can see.
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