RatGDO can do this without the need for a magnetic switch. It’s a simple ESP32 board with easy-to-terminate wire terminals. It also lets you control the lights on your opener, see the current status of the door, and even open the door to an exact in-between position (if your door supports it).

You can program your own ESP32 if you like, or buy one from the guy that made it directly for ~$40.

Still - props to you for making your own solution! I know it’s extra satisfying when you can homebrew your own smart home solutions from scratch - just wanted to share another solution for people who don’t have the same skills.