Master station on delay is only positive and off delay is only negative so that won’t work.
Looks like the only way to accomplish this is with parallel operation (uncheck sequential). If I have a spare/open zone before my regular zones, say zone 1, then regular zones 2-6,with 7 as master and 8 unused I can connect 7 and 8 together with a jumper so either one will turn on the pump. Then program 8 as a non-sequential zone. Say I want to run 20 minutes per zone. 6 zones is 1 hour, 40 minutes total. Set run time for zone 8 to 1 hour and 30 minutes. I am setting zone eight to slightly less than the end time to avoid the pump running past the end of the last zone. If I wasn’t worried about that I could just run the master as a non-sequential zone and maybe that would work fine but with delays between zones and such the exact end time is hard to determine and may not be accurate. Set zone 1 to 30 seconds (first zone usually takes a bit longer to build up pressure). Set the delay between zones to 15 seconds. The master station will shut off during the delays but zone 8 will keep the pump on during those times.
Complex but that’s the only way I know of to do this. I welcome other suggestions.