You can only run ONE Preset at a time in generator. If you load a different Preset, it will clear the first.
It sounds like you may be referring to Programs in a sequence with your question, however. For remote use, if there is any killing happening within programs, the recommendation is to have to more than 4 hours between repeats, as the programs are more effective with a shorter repeat cycle. Two hours is even better than 4 hours when killing. When running all healing programs, there is some room for extra length - for instance, if running vitamins, etc., you may only want the program to run once or twice per day, so would make adjustments as desired.
For more details, please check the link: