Does NWELL have any impact on NMOS?
For NMOS transistors, you would typically be concerned with the substrate type, which is usually P-type. The Well Proximity Effect (WPE) is more relevant to PMOS transistors, as it involves the impact of the N-well on the characteristics of the PMOS transistors.
In summary, for NMOS transistors, you would generally consider the substrate type, and WPE is not a significant factor for NMOS. WPE is more relevant when dealing with PMOS transistors formed within an N-well.