In order to allow flex programming for zones not exposed to the elements (plants in covered porches, hanging baskets under roof eaves) introduce an option to ignore actual and forecast precipitation data when calculating daily moisture balances for the selected programme.
I was wanting the same thing. My work around is to set 2 watering schedules. The first is a fixed 3-day schedule starting at 3am. This is for the covered plants (currently 24 minutes). This zone has the skipped rain function off.
The second schedule is a flex schedule for all other zones and starts at 4am.
Yes I’ve done something similar but I would like to have a flexible schedule for the covered items which does a moisture balance calculation allowing for variation in transpiration, manual watering etc but ignores rainfall and determines the amount of watering required on that basis.