Structure block bounding boxes incorrectly appear to preserve transformations when switching modes

If a structure block in Load mode is displaying a bounding box with a transformation (a rotation or reflection), and the structure block is then switched to Save mode, the visual bounding box will remain in place; the size, position, and transformation are all preserved. This is only a visual glitch; the true bounding box is not transformed, and so the visual bounding box does not correspond to the actual region that will be saved by the structure block.

Steps to reproduce:

1. Place a structure block, set to Save mode, enter a structure name and dimensions, but do not press SAVE;

2. Switch the structure block to Load mode, and select a transformation (e.g. a 90° rotation);

3. Switch the structure block back to Save mode, and note that the transformed bounding box is still displayed;

4. Press SAVE, then load the structure somewhere else, and note that the saved region does not correspond to the region marked by the displayed bounding box.

See video for a more detailed explanation: https://youtu.be/Y_ebGlPC7Xo