Sounds similar to my setup. 47 minutes could be accurate... depends on the frequency. Warm season grass supposedly roots at a lower depth than other grasses so the watering duration needs to be long enough to reach the projected root depth (9 inches default if you haven't changed it). If that is longer than you usually water, you can play with the Advanced->Root depth setting. Making it shorter, 5-6 inches will reduce the duration and increase the frequency. I took a very unscientific soil plug with a shovel and only observed 2-4 inches root depth on my Zoysia grass (sod is 1 yr old) so I dialed back the root depth and am slowly increasing it over time. The hope is that the roots will grow longer and the grass more drought tolerant. April/May in FL is not the time to underwater.
I think this is just a way to manually delay all schedules from running. If your schedule type, WAN (water as needed), flex, etc. has weather intelligence turned on then it should automatically skip based on the rain threshold you set.
I think the Rachio assumes each zone is empty when you first start it up. Ideally it would check to see what the conditions have been when you first set it up and schedule accordingly, but I don't think it's smart enough yet. If you're running a flex schedule, you can set each zone to full manually and it will adjust accordingly.
As far as I can tell, there are 2 factors that are taken into account when you pick a nozzle.
Nozzle Type - misters, emitters, and bubblers should be placed on separate schedules than rotors, rotators, and spray heads. Determines zone default efficiency. Also important to set/schedule properly because the presence of these nozzle types disables Smart Cycle.
Nozzle Precip Rate (PR) - Determines how much water each nozzle produces in in/hr.
For my drip line schedule, I calculated each line was putting out 1 in/hr and made a custom Emitter nozzle. Hope this helps.