Double Die & Mechanical Doubling

1. The entire side of the coin does not have to show doubling to be a doubled die.
2. Hub doubling is hub doubling regardless of how much magnification it takes to see it. The question then becomes whether anyone would care?
3. Doesn't matter how many letters show signs of doubling, that alone doesn't define a doubled die versus Machine Doubling.
4. The difference lies in the fact that hub doubling (doubled dies) show a doubled design on the die that creates the coin. Machine Doubling is any one of a number of forms of doubling caused on a coin by the die bouncing or other defect of the coining press. The difference is very distinct in appearance, and takes a little experience to detect.

My suggestion is to buy a doubled die from a reputable source and compare its merits against what you've been finding. The difference should be rather obvious with a little study.