This is a P0 due to it resulting in data loss.

Open a QML file with several elements. Collapse some in the middle of the file with code folding. Make sure they were multiline nested Elements that you folded. Move the cursor to any line above the folded items. Now hold down CTRL + Shift (CMD + Shift on the mac) and start pressing the down cursor key to move the selected line down through your code. As it passes through any collapse items it destroys the content.