i dont spread it and i think its better than spreading it. my reason is that the cpu die is in the middle and the mean cover wont transfer the heat outwards, just upwards.
Since the CPU is a lot of metal, it will transfer the heat everywhere on it, including outwards, making the whole top of it warm, so I would say it's a good idea to at least get a light layer on the outer parts.
i dont spread it and i think its better than spreading it. my reason is that the cpu die is in the middle and the mean cover wont transfer the heat outwards, just upwards.