In terms of hardware composition, Snapmaker 2.0 Dual Extrusion 3D Printing Module features a proximity sensor, while Artisan Dual Extrusion 3D Printing Module does not.
In terms of calibration processes, Snapmaker 2.0 Dual Extrusion 3D Printing Module uses the proximity sensor to detect the distance between the nozzles and the heated bed[1]. Without the proximity sensor, Snapmaker Artisan Dual Extrusion 3D Printing Module detects the leveling stats of the heated bed by touching the build plate with its left nozzles. The same technical principle is applied to both modules' Z offset and XY offset calibration.
[1] Snapmaker 2.0 Dual Extrusion 3D Printing Module features both proximity switch and optoelectronic switch. Yet, the optoelectronic switch is only used for Z Offset Calibration. If the optoelectronic switch is also applied to Mesh Bed Leveling, the platform of 2.0 will slightly warp after the nozzle touches the build plate, which will further decrease the accuracy of Mesh Bed Leveling. This also means glass plate is only compatible with 2.0 in the situation of manual leveling.