For each program, you can set it to repeat many times a day, by either specifying the second start time, or use the ‘repeating every’ option.
Both the microcontroller-based and Pi-based OpenSprinklers run the same unified firmware. If you choose OSPi, the basic functionalities are the same, except it doesn’t have LCD, buttons, and you need to provide an RPi. There is NO need to trigger programs via bash.