Here is a quickie hackie script to help (maybe)…
Display order is simply a level number (integer) in Rhino. By default, when created, all objects have level 0. SendBackward subtracts 1 from the level number; BringForward adds 1. BringToFront and SendToBack naturally send objects to the level top+1 or bottom-1 of all the values the level values list.
It is possible to attribute a specific display order level directly to an object via a script. To use the script:
Select an object to change its display order, then (optionally) select a collection of other objects to analyze their display order. A message box will appear with the current display order of the object to change as well as the max and min order levels of the other objects (if there were any selected). You can then enter a new display order for the object to change.
SetObjDrawOrder.py (1.6 KB)