Nice one @Jarek !
below one python script to toggle the highlight (without using display mode).
import Rhino
import scriptcontext
import rhinoscriptsyntax as rs
def ToggleHighlight():
ids = rs.SelectedObjects(include_lights=True, include_grips=False)
if not ids: return
objs = [rs.coercerhinoobject(i) for i in ids]
for obj in objs:
if obj.IsHighlighted(False):
obj.Highlight(False)
else:
obj.Highlight(True)
scriptcontext.doc.Views.Redraw()
ToggleHighlight()
c.