Tried to scaled a layer way beyond the canvas and perhaps beyond the ASP memory allotment. Waited for a long time, then it crashed. When trying to re-open it takes forever then either crash or freeze. Had to wait long time then delete the layer. Ended up having blown it in a separate artwork, crop to the canvas, then copy/pasted to the original one.
I wonder if this feature can help to solve this: adding an option to crop to the canvas boundaries when process scaling up (maybe in "more"). This is needed when the canvas is already hi-res and you need to blow a layer detail "out of proportion".