Hi MB2002,
What happens if you deliberately fly (A/THR OFF) into PFD's VMAX and beyond?
The AP will only disconnect and the aircraft pitch up for the high speed protection (green dashes in VMO / MMO tape). It will happily let you exceed all Flaps / slats speed limitations. E.g. If you accelerate too quickly with AP & A/T engaged whilst the Slats are being retracted to 0.
In the old days we used to control the rate of acceleration by retarding the TLs a bit and respecting the placarded speeds. Manual thrust control or selecting a sensible speed, when the AT is engaged, would earn you extra Brownie points.