I've been thinking about #1 a lot - for the most part not many people need to know what comes up and it is distracting. If I were to make my own implementation

I've been thinking about #1 a lot - for the most part not many people need to know what comes up and it is distracting. If I were to make my own implementation I thought about adding a 0.5-1 second delay after key-up before fetching results but it obviously wouldn't be "instant". In my opinion the behaviour of "Turn instant off" should be that the instant UI is still the same, but results aren't fetched until the user presses Enter, and have a third option for the old functionality.