1. If you click "Pause" in the Control tab for that generator, and leave everything as-is, and it is still in the same position when you get back, you can click "Pause" again, and it will continue exactly from where it was.
If you click "Stop", or if there is a power loss, etc., making it necessary to restart: Be sure to note the Preset number. You will have to re-enter this when you restart the Terrain. This will restart this the chain at this location, although any time spent in this Preset will be repeated. There is a document in the Files section with details on restarting a Preset.
2. It is ALWAYS a good idea to screenshot the generator screen to maintain documentation of present location if you decide to try the Pause for several days.
For more details, please check the link: