This is my first entry altogether. I already have a working prototype of the project but there are a few problems with the thing:

1. The ESP-12E does boot up very erratically
2. The SPI communication used does not allow to reach all the data (just the first 64 words out of around 200), switch to the I2C is needed
3. I believe that the device is not safe from the voltage spike, because there is not enough creepage distance from mains to the ground near the linear transformer primary; also it probably lacks TVS diode
4. The relay is not switched with the MAX78615 zero/crossing in-built switch, just with the ESP GPIO, but the relay could be removed altogether

I would greatly appreciate any comments regarding the European grid mains safety to implement them in the second iteration of the PCB. Thank You.