maybe it would be good to have some sort of (general) index of compatibility for consumer products. A one-number thing. "how likely this product is to lock you

maybe it would be good to have some sort of (general) index of compatibility for consumer products. A one-number thing. "how likely this product is to lock you out of something good". If this information is valuable (and I think it is!) even small fluctuations on the index could push a given product up.