I am using the SCREEN_PROPERTY_MODE property (screen_get_display_property_pv) to set/change the graphics mode. These 
mode changes have an impact on graphics output and display synchronization, so it is important to know when the mode 
change has been fully applied. However, the method for doing this is not clear.
Mode change time seems to vary drastically, taking 250ms one time and over 1.5 seconds the next. Mode change time can be
 seen from monitoring screen slog information as well as looking at the display.
I read the mode properly after setting (which flushes the command), but it returns the new mode even though that mode is
 not yet applied. I tried an explicit flush command, but that had no impact. I also tried "wait_vsync", to no effect.