I have been using leap.js through the browser for quite a while (years). There is a repeatable issue with the pinch strength being detected incorrectly when near the limits of the leap motion camera view.
Essentially, the pinch strength will change when a hand goes out of view - probably incorrectly.
Is there a way of knowing when a hand is near the viewing limits? I can easily ignore the pinch strength when near the camera limits... this would also be useful when detecting rotation.
I do know about the interaction box - I don't think this is useful - since it only gives a box location relative to a defined size - this doesn't indicate whether a hand is near the limits of the view.
I have added a check against hand.confidence, but it doesn't seem to be useful - but that could be my understanding...