According to the A320 FCOM, capter 22 auto flight, flight guidance, the "automatic speed mode protection" of the auto flight system of the A320 disengages the flight directors upon reaching current VMAX+4kt which will cause A/THR to revert to speed mode. But this protection is only active in climb modes: CLB, OP CLB and EXP CLB.
Does anybody know why the "automatic speed mode protection" is not available in SRS vertical mode where A/THR is also in THR CLB mode?
Also does anybody know if this protection uses the VFE of the selected flap config or of the actual config? E.g. if you are in climb and inadvertently select flaps from UP to CONF ONE then the aircraft won't let you do that but does this (cruise lock) but as far as I know the speed tape on the PFD already shows the maximum airspeed for the selected flap 1 config. So does this already disengage the flight directors? Or do they use the actual flap position or overspeed warning from the flight warning computers?