I see that one of the more talented among us has yet to answer your question, so I'll do what I can to help.
I am currently in the process of setting up my first smart plug (TP-Link HS105) to work with my Echo Dots. It will control a lamp.
Sidenote: I've read of some people that think they have to have an Echo to have a Dot. So unless you just want the larger Echo as well as the Dot, you don't HAVE to have Echo. I have 3 Dots and no Echo.
Yes, it is possible to use your Echo or Dot to set a schedule for your porch light without daily commands. Without having an Echo, I am 99.5% sure that whatever is on your Echo's To Do list will be in the Dot's and vice versa. That's the way it works with my 3 Dots. Now, we only have one Amazon account. I don't know what it would be like with multiple accounts. I guess if one device had a different account from the other device, you'd have separate lists.
Another product I'm going to be trying soon is a TP-Link wifi smart LED light bulb. It connects to your router like like the plug and iirc you can set it up on a timer as well via your KASA app. That way you won't have an electrical cord running down your outside wall. Hummm, you might need to check to see if they are rated for outdoor use. This is the one I'm considering. If I were to use it outdoors, my particular set up would have it in a location where it couldn't get wet but you'd still want to call TP-Link
My HS105 mini plug (thanks Mike!) is installed and working with my KASA app. I just need to introduce it to Alexa
Good luck!
Smart Wi-Fi LED Bulb with Dimmable Light
LB110
Manage Remotely – Control your lights from anywhere with your tablet or smartphone using the free Kasa app (iOS, Android)
Dimmable Light – Adjust brightness to suit your mood
Voice Control – Pair to Amazon Alexa to enable voice control
Monitor Power – Track real-time energy used to stay informed
Save Energy – Reduce energy use up to 80% without brightness or quality loss compared to a 60W incandescent bulb
No Hub Required – Connect the bulb to your Wi-Fi at home