Smart can be adjusted to a degree to try and get it watering every day for some amount of time, however, if you (or your plants) require an exact amount twice a day, then I’d suggest using a Custom program with Smart enabled for the system but not always for the zone, more on that later. This will enable our servers to monitor your weather and delay a Custom program (delay = cancel in this sense) so that it won’t water until the following day.
You can use a combination of Smart and Custom because Smart takes into account how much water the system applies and how much rainfall there is. I do this at my house. So, you could input the landscape variables as accurately as possible and enable Smart for the zone and then still create a Custom program that will run every day twice a day for as long as you think it needs and let Smart do any additional watering it calculates is needed above and beyond what your Custom program is already doing. This way if there’s a particularly hot day Smart will adjust for it and if there’s any rain, Smart will adjust for that too. This way you’re ensured to put water on the plants every day but not over do it and not waste water if it has rained a sufficient amount.
Also, you can set the thresholds for a rain delay in the Device Details screen under Weather Adjustments. This way you can make sure it only delays if there is a certain percent chance of rain and a certain amount of rain forecast. This helps avoid false positives due to proximity of the forecast center point.
Hope this helps!