Example of how a new stretch effect would work, for https://scratch.mit.edu/discuss/post/8533032/ The stretch factor is a multiplier for the width/height of the box. Area is kept constant no matter what the factor is, so the effect won't interfere with the sprite's size. Negative = vertical stretch, positive = horizontal stretch. The stretch factor is scaled so that -100/100 = 5x as tall/5x as wide. The slider is limited to this range but the effect isn't actually limited, you could make an 100,000 pixel wide box if you wanted. IMO this is the most intuitive way of stretching a sprite. It doesn't compromise on any point that I know of. (technically the line width should change based on the stretch factor)
