Do knock sensors really allow the engine to advance indefinitely? (Theoretically)

[imzjustplayin]

On the civics before 1996, they did not include a knock sensor, and the ones 1996 and above do because OBD-II requires a knock sensor. The advantage of a knock sensor is to prevent the engine from knocking, the ECU tunes the ignition timing until it knocks (supposedly). Now I'm wondering, does the ECU on the Civics have a limit to how much it can advance timing? Is there a top end to how much it can advance ignition timing?

Supposedly with the knock sensor, it should be advancing the timing as much as possible right before it knocks. But what if I were to remove the knock sensor from the motor so that it still "functioned" but wouldn't be able to detect a knock? Would it advance the ignition timing, causing it to eventually knock/ping and then blow up since it doesn't know when to stop?

Cause if the whole knock sensor allowing more ignition timing were true, we wouldn't need to tune our ECUs when we put in a turbo now would we?

One point I forgot to mention is that it is said if the car is "designed" for regular gasoline that it wouldn't benefit from premium. But if the car's knock sensor is the only thing preventing it from advancing timing, then wouldn't premium gasoline allow it to advance the timing further, therefore leading to better performance and possibly fuel economy?