My esp-01 x10 Alexa controler had been working flaw less untill we got a new modem. Today I thought I'd get to updating the code to allow the new modem connection. I decided to look at the possibility of a new sketch for it. Or to see if there had been any new developments.
The Ardiuno ide programing application was updated so just maybe some sketches were too.
I discovered a esp 8266 sketch by Aircookie
https://github.com/Aircoookie/Espalexa this combines the wemo as well as the hue sketches into one allowing diming, color and speed control in addition to just on and off. Reading through the README and looking into the code it is explained that the number of devices possible is limited by the boards memory.
Since the sketch I was using was originally created for the esp-01 I thought I'd try it on a spare wemo d1 board I had laying arround. I don't use any dimming commands so I stuck with my original sketch adding 16 X10 devices just as a test. I found where the device limitation was added to the code and changed it to 16 and it does allow Alexa to see and control all 16 devices I added.
The wemo hue combo sketch states a max of 128 devices but it is coded for 10 by default. I don't use even 20 x10 devices with Alexa from both homes so this is a very reliable and cheap way to do Alexa x10 control.