Ideally, there would be an Event Binary Sensor. You would configure it to listen for events to set its state to on or off. However, it does not exist. What does exist is the MQTT Binary Sensor which can be configured to subscribe to a topic whose payloads set its state to on or off (but you’ve stated you don’t want to use MQTT).
The simplest option is to do what you described:
However, this approach requires the combination of a Input Boolean and a Template Binary Sensor whereas the same result can be achieved with just an MQTT Binary Sensor (i.e. half the quantity of entities if you were to use MQTT). It’s something to consider if you have many sensors to configure.
Should you change your mind about using MQTT, I suggest you consider employing Strategy 2 in this post.