No, it’s not. If you don’t use your MacBook regularly, the system will never accurately determine when it should hold the charge at 80%. Even on the iPhone, it doesn’t work well. I wake up every day at 5 AM for work. When I go to sleep, I notice that the system is holding the charge at 80%, only to release it to 100% at... 3 AM. Even some Google phones are smart enough to sync the battery charging with the alarm time.