Is a 5-second preview enough to judge video object removal?

I'm on the remover.work team. We currently let people preview the first 5 seconds before running a full video cleanup.

Would that be enough for you to judge whether the result is usable, or would you need to choose a difficult section later in the video? For example, the object might move, the camera might pan, or something might pass in front of it.

What would you want to check in a preview before spending credits on the full clip?