A FFP reticle will cover no more of the target at 15x as it does at 3x. So your fears of not being able to see an animal at max magnification is unfounded, unless you are shooting field mice at 1000 yards. Not a joke, we have shot squirrels at 741, 852, and 1201 with FFP scopes.
Your fears of not being able to see the reticle at min magnification depends on your eyes and the reticle. It is basically a fine crosshair at min. If you can see a fine crosshair SFP, you will be fine.
Rocks are at 741 yards
3x
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10x
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20x
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24x
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This is at 545, on 24x, and is a truer representation of what your eyes see when looking through the scope.
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Target is at 200 yards.
3x
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10x
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24x
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