Hi I use the replicator 1 dual with GPX. It's almost the same setup as with the 2x, but you have to change the start and end gcode in Kisslicer, as well the ini file of gpx to use the x2 setting.
You probably can start with my settings / short guide, when you have questions, please let's hear. (it's for mac, but if you want I can edit it to windows).
Bart