I don’t speak French well, but it looks like these run in the Smart Life app. So your easiest solution will be creating virtual switches in ST and using IFTTT to control the device in Smart Life. This will at least give on and off control. One IFTTT applet for on, and another for off.
You’ll need zwave / zigbee switch’s with their default DTH and use smartlighting app to completely remove the cloud delay. Anything less there will be some cloud delay with smartthings, how noticeable it will be will greatly depend on your setup and location.
You may also want to consider Hubitat if you truly want everything local.
Even with Tasmota, you are going to need a custom DTH which means the ST cloud is going to get involved.
Also, if you use any custom automation, the ST cloud is going to get involved. There is no real way to completely remove the ST cloud from the picture because it is a cloud dependent system.