I would like to suggest an improvement to the schedule feature of your smart plugs and switches and of course the Kasa app.
I do like the ability to use sunrise and sunset times in the schedule. For me it could be even better if we could specify an minutes offset from sunrise and sunset. For example, I want my indoor lights to turn on "15 minutes before sunset" because it gets dark inside before the actual sunset. So if we could specify a number of minutes (0 - 60), before or after, sunrise or sunset in the schedule it would be most helpful.
WORKAROUND: Here's the workaround I'm using which was suggested by @Grandpa-Ron.
I wanted my indoor lights to switch on about 15 minutes before sunset. I installed IFTTT app on my phone. In IFTTT I created an applet which uses the Weather Underground widget as the trigger and the Kasa widget for the action. I found a city which has a sunset about 15 minutes before my home town and used its sunset as the trigger the lights to switch on. Has been working great for me.
Of course it would still be easier if the Kasa app could just allow an offset for sunset and sunrise. But I guess that will have to wait.