Depends how you want to use it. If you want it in your car, this seems like a good mod.
Obviously there’s a trade off between activity and battery life. But if the device sent out its “I’m here” signal less frequently, then it would be less useful. If I want to unlock my door when my presence sensor arrives home, I don’t want to just stand in front of the door waiting for the next presence sensor ping to the hub.
There don’t seem to be many. This one was announced recently but no one knows when it will be available.