I switched to Shelly products years ago. It's a different world. I still have an Intertechno Gateway to give away

The ITGW-433 Lan gateway can only be used with intertechno radio receivers. If you wish to operate blinds/shutters or garage doors controlled by Somfy or other third parties, you must install an intertechno radio receiver in parallel. For example ITL-500 (1204316 1) /ITL-1000 (1204305 1) , then it will also work with ITGW-433.

Yes, it is included with

According to our information this is compatible.

Yes, no problem. However, be careful with the dimmer if you do not have a visual control there is a risk of being in a permanent cyclic state (variation from minimum to maximum until the next command)

Unfortunately, no. I couldn't find any alternative. I'm sorry.