No on Magellan, "Opus Backdrop" does not refresh the Workbench.
AmiStart also has a Refresh but it only works on its bar.
I think it should not be difficult to create a small command to do a Workbench Refresh, if any developer would like to do it we would be very grateful.
I will do some research if there is any source or OS3 script that can be adapted
EDIT:
Found on Aminet "SmartW" C-Source is included.
Tried to compile on AROS x86 it but I get compile errors
http://aminet.net/package/dev/src/SmartWB10
IconClone works wonderfully on AROS One x86.
Thanks to @paolone for requesting the command line options.
The Wanderer Backdrop works well to refresh.
This is what I did for testing. If you are going to be changing volume disk icons and you are unsure just copy AROS:Disk.info to AROS:Extras or anywhere that isn't a volume.
Simply go to AROS:Tools or wherever IconClone is located. Launch the program with the app icon or open a shell and type IconClone --o please note there are two dashes and that is the small letter 'o' not the number zero. The empty GUI should open on Workbench. More about that in a few.
Drop the AROS: icon in the destination display area on the right. Drop another icon, such as Ram: like I did, on the source display area on the left. Then perform the exchange.
Do the Wanderer Backdrop trip and the disk icon images change to the new ones. To restore the disk icon from backup do this. In a shell type IconClone --o AROS:Extras/Disk.info to open the original disk icon in the source display area on the left. Note that disk.info isn't visible in ICON VIEW. It's hidden from view. Drop your now changed AROS: icon on the destination display area and perform the exchange. After the backdrop trick it re-appears and the icon has been restored.
If you prefer to do it all at once to restore the disk icon since we know the locations, in the shell type IconClone --o AROS:Extras/disk.info AROS:Disk.info and the GUI opens and both icons are displayed. Just press the exchange button.
Beware though if we leave out the --o the command is IconClone AROS:Extras/disk.info AROS:Disk.info. This is the command line exchange for scripts. There are no prompts or messages. It simply exchanges the icons with no GUI.