Hi,
Local tuya integration works flawlessly but you have to make it local first. In my experience with tuya light switches, the problem is that all tuya devices are connected to the cloud regardless of local tuya integration. People tried to solve this problem with tuya convert but tuya strikes back and made switches that are very hard or nearly impossible to convert.
But I found a way how to get rid of tuya cloud and truly use local tuya integration. I tested this on my tuya wifi smart light switches.
Things you need:
tuya wifi smart light switch
smart life app
router handling all your local wifi devices - not isp router
adguard
local tuya
tuya iot account
I will explain this on a wifi smart switch but I believe that it can be done on other tuya devices connected to cloud.
When you install smart switch put it in pairing mode and add a new device on smart life app. After that go on tuya iot platform and get a local key for that device. With local key add this device to local tuya integration.
Now, if you check your smart life app you will see that device is still on line in smart life app.
To disconnect devices from the cloud you need a local router. I have a router that acts as a gateway to my isp router and all wifi devices are connected on it.
You have to install and configure adguard for handling local dns request.
On my local wifi router under dns1 and dns2 for wifi and lan I wrote ip address of my homeassistant server as it handles local dns request. Its important to write both dns with the the same address because devices will use google servers if they cant connect with first dns.
After that my tuya switches cant connect to the cloud any more. If they can check dns requests in adguard and block tuya. On my smart life app all devices are offline, but as I configured them first using local tuya integration i can use them locally.
And on more thing. I have multi way switches. ie in hallway, meaning two or more switches are control one light. I used this solution
https://community.home-assistant.io/t/emulate-a-three-way-switch/167863/2?u=dadopq
In the end this is my solution how to make my tuya switches truly mine without soldering,uploading firmware, or using tuya convert. And they do work as local devices.