Flex schedule on a complex yard in SoCal

We (meaning my husband) installed Rachio a few months ago when CA had a ton of rain. We set up a flex schedule, and everything was moving along nicely. Now, daily highs are in the 80’s, and I’m having doubts.
When the zones were set up, we did check our soil type (sandy loam) but our yard is large and on a steep slope; we have issues with runoff. But we also get so much sun that our hills and ground cover are crispy. I’ve since done some reading on the community page, and change variable such as riot depth, and depletion, but with a new flex schedule setup Rachio wants to water everything heavily, and then basically leave it for a week. Which means I’ll need to manually water from the get go, defeating the purpose of the flex schedules. Should I give up now, move to a fixed schedule and then work on a flex schedule come fall?

what are you watering, grass, shrubs, etc?

It’s a mix - trees, ground cover on the slopes, shrubs/perennials/annuals in the beds. Where we are many annuals are actually perennials too, and for added complication we have zones with a mix of all types of plants. I think we’ll start with a fixed schedule so we have more control, and then will tweak zone settings so that the flex schedule, if we were to run it, would water the same time/frequency - that way I know we have the right settings. Is that a good way to approach it?

It’s recommended to not start on Flex, and then just turn on one zone with dialed in settings and you can see how it does and play around with it.