These are drivers I've written myself.
You need to flash the Sonoff kit with Tasmota or ESPurna, see https://github.com/xoseperez/espurna/wiki or https://github.com/arendst/Sonoff-Tasmota/wiki.
You then need to setup an MQTT broker either locally or in the cloud, see https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-the-mosquitto-mqtt-messaging-broker-on-ubuntu-18-04.
My driver does not currently support SSL so I use a local MQTT broker and rather than open firewall ports to it I bridge it with a cloud based broker eg. AWS IoT or Digital Ocean as above.
I use MQTT Dash on my Android phone, https://play.google.com/store/apps/details?id=net.routix.mqttdash&hl=en_GB, which enables me to setup simple buttons etc. to issue commands to my Control4 system.
I also have a simple Relay Light driver that allows you to connect lights up to Sonoff relays and they then appear as normal Control4 lights.
Very good kit and very fast interface/control.
If you would like to play with the drivers I have in beta then send me an email address and I'll email you the drivers. I assume you are able to install drivers on you Control4 system?