@Mad (Flt) Scientist
I'm awfully sorry to disagree. Like I already mentioned, my FCOM (A300) says
"Max. operating altitude for slat operation or flaps extended is 20 000 ft."
So it clearly distinguishes between slats extended and slats operation.
What do you think is the chart for (it is also of my FCOM and suggested if you fly for whatever reason with slats extended) ? Is there a doted or red line at 20k feet?
Kind regards