KC868-A8 12v output?

[admin]

1. 277VAC 10A is MAX support load ability. your door or gate, relay is enough to use. don't worry, no problem, relay both support use for DC and AC.
2. if you use our KC868-A series board, that made by ESP32, you can use ESPHome integrate to home assistant. ESPHome config file support use "hold" and "toggle" mode. here is some config details:
https://esphome.io/components/button/index.html