Well...........
If the AP is in, there will be speed variations, 90% of the time, they are transient and if the Vapp is adjusted correctly after Config Full, all should be well, even in thermic conditions, CUN, SFB, LAS etc.
GS mini is busily doing it's thing while all this gusty thermal stuff is going on as well - the target Vapp will usually be dancing around.
Now, if said AP is out, and it is thermic, you need to be aware of the shortcomings of the FBW system that will tend to exaggerate PIO on final. The onset of power by the autothrust should be countered by a sympathetic amount of forward stick as the operative cannot think/act as fast a the AP. Vice Versa for reduction of thrust.
I was fortunate to have had full factory courses for 320 and 330 and personally would not fly manual thrust unless exceptional circumstances prevail or in the sim. Let's face it other aeroplanes are autothrust all the time as well and that is the way Airbus designed their aeroplane
Boeing went another way, which is fine for Boeing.............. Not for Airbus
