```python
import os
import tempfile
from pyaedt import Hfss3dLayout
from pyaedt.generic.filesystem import Scratch

# 1. Creates a temporary folder and prints its path
temp_folder = tempfile.mkdtemp()
print(temp_folder)

# 2. Downloads an example file into the temporary folder
# Assuming example file URL and name (This part needs an actual URL to work)
example_file_url = "http://example.com/example.aedt"
example_file_path = os.path.join(temp_folder, "example.aedt")
# Use requests or similar method to download, here's a placeholder
# import requests
# r = requests.get(example_file_url)
# with open(example_file_path, 'wb') as f:
#     f.write(r.content)

# 3. Sets the non-graphical mode and launches AEDT in graphical mode using SI units.
os.environ["PYAEDT_NON_GRAPHICAL"] = "False"

# 4. Initializes AEDT and launches HFSS 3D Layout
hfss = Hfss3dLayout(projectname=example_file_path, specified_version="2022.2", non_graphical=False, new_desktop_session=True, machine="local")

# 5. If the AEDT file already exists, it removes it and saves the project in the temporary folder.
if os.path.exists(example_file_path):
    os.remove(example_file_path)
hfss.save_project(os.path.join(temp_folder, hfss.project_name))

# 6. Prints the boundaries from the setups object
print(hfss.design_properties)

# 7. Hides all nets and then makes only two specified nets visible
hfss.modeler.nets.set_visibility(False)  # Assuming this method exists or similar
specified_nets = ["Net1", "Net2"]
for net in specified_nets:
    hfss.modeler.nets[net].visible = True

# 8. Plots the two specified nets
for net in specified_nets:
    hfss.plot(net)

# 9. Makes all layers visible
hfss.modeler.layers.set_visibility(True)

# 10. Changes the color of a specified layer
specified_layer = "TopLayer"
hfss.modeler.layers[specified_layer].color = (255, 0, 0)  # Setting color to red

# 11. Disables the visibility of components for the top and bottom layers
hfss.modeler.layers["Top"].components_visible = False
hfss.modeler.layers["Bottom"].components_visible = False

# 12. Fits all so that all can be visualized
hfss.modeler.fit_all()

# 13. Closes the project and releases the desktop
hfss.close_project(saveproject=False)
hfss.release_desktop()
```