Flex or Fixed with a once a week water restriction

Living in Austin Texas we have a once a week water restriction. Automatic sprinkler systems may operate between midnight and 5 a.m. and between 7 p.m. and midnight on my watering day (Wednesday).

Given this do I use Fixed or Flex or a combination of both?

Pro: I also love the idea of season updates automatically adjusting my watering times.
Cons: The Initial setup times are based on a 3 day a week andI have no idea how much time each zone should be given a single day. Season updates updates the time but assumes that my guess on times were correct. As I am fine tuning the zone variables the times don’'t adjust. I am now having to make more guesses on time.

Pro: Automatically changes based on adjustments to the variables of each zone. It has a pretty simple 5 level more/Less scale on watering time if an zone is not getting the water it needs vs me guessing how many minutes to add.
Con: Times don’t adjust only water intervals. Since I can only water on Wednesday I am kind of stuck with how I initially set it up.

Is my best option to set my Fixed times to mirror Flex as a starting point?

In this limited scenario, flex will probably always be watering, since even if it doesn’t have to (let’s say it rained the day before), it will look forward to when the next time it can water, and will determine that next watering is 7 days out, and will more than likely water.

Flex might be safer than fixed, especially if you have weather intelligence (virtual rain sensor) enabled. Fixed doesn’t look ahead, and might skip your schedule based on rain received today/yesterday but not taking into account next watering.

The watering times are difficult, since a zone can only absorb certain amount of moisture before saturation.

Maybe start with flex, see how it works, and if not desired switch to fixed?