That's a good question. You have to understand two things. Freezing for at least 24 hours means that the contents are actually frozen. Because liquid is not ice cream but something else. Whether it is frozen for 1 day, 1 week or 1 month doesn't matter to the appliance, the main thing is that it is frozen.
The second is the shelf life of the food used. This will also go bad in the freezer at some point. If you leave it in there for 10 years, I personally probably wouldn't eat it any more.

I often have a little left over from a cup 😅 I always put these back in the freezer. It was just as good after a few weeks as it was after 24 hours!

Works too! It always depends on the temperature. As soon as the entire contents of the container have reached the temperature of the freezer, which is the recommended 24 hours, that's all that really matters. The official recommendation is around -12° to -25°, so you can experiment.