Personally, I have everything bound up into bind files with the number padm but this does sound like a good idea.
But please, when you are adding this third tray, please give us a bind command to allow us to change the second AND third trays using bind commands.
At current, only the first tray can be swtiched to a specific tray via a bind.
The second tray can be switched, but it's a PREVIOUS | NEXT thing and if the binds get out of order, it messes things up.
Perhaps the following could be created:
MAIN TRAY (currently exists): /goto_tray 9
2nd Tray (does not exist): /goto_tray_2nd 8
3rd Tray (does not exist): /goto_tray_3rd 7
