In a system where the evaporating temperature is -8oC, and the suction line pressure drop is 2K, the saturated suction temperature (SST) will be -10oC. This is fine.

What I would like to know is why doesn't superheat affect the SST? In this same system, if the total superheat (evaporator plus suction line) were to be e.g. 10K, then why is this 10K not added into the equation to obtain the SST? Of course, it is not added, but I would like to understand why?