@Daan_Seuntjens I don’t know exactly why the points are scaled by 2, but suspect it’s similar to what was done in YOLOv5 for the bounding box centerpoint prediction, which was to help address a few issues.
The point offset range is adjusted from (0, 1) to (-0.5, 1.5). Therefore, offset can easily get 0 or 1.
So instead of being bound to the range [0, 1] the values are shifted and scaled to [-0.5, 1.5] which was supposed to help reduce grid sensitivity for predictions. It’s not directly answering your question, but you can see some of the discussion around it on this issue Want to figure out critical algorithm of Detect layer · Issue #471 · ultralytics/yolov5 · GitHub which might give you a bit more context about the formula and how it was decided on.