“We have a few thousand demonstrations. Should we collect more, or is there something valuable in what we already have?”
We don't guess. We find the turn.
Every corpus has a point where more of the same stops paying and rebuilding starts.
That point is not a rule of thumb — it moves with your tasks, your robot and how the data was collected. So we locate it on your data and tell you which side of it you are sitting on, before you commit to anything.
Below the turn we would make your policy worse, and we will say so — collect first. Above it, the episodes you already own are worth more than they are being asked to do. The deliverable is knowing which, and by how much.