How to adjust for height and finger size in grading

Consensus and average grading are how most think grading should be. This is normally correct but when it comes to height and finger size it is not the best practice. Let us say there is a boulder that feels like 8A if you are 155 cm, and then it drops one grade for every ten cm you add, i.e. a 195 cm tall guy think it is 7B. It is easy to think such a boulder should be graded 7C. This would mean that it would be popular especially by the very tall guys getting a very easy 7C tick. In other words, such boulder could instead be graded 7B+ morpho to better reflect the difficulty for the guys focusing on such (dyno) boulder. It is also the same thing with finger size and kids and short female doing hard routes just because their physics better are suited to that finger pocket 8A a bigger FA put up.