Our FCOM is quite clear: Upon arrival of a new crew taking on the aircraft perform a COMPLETE preflight inspection. It’s not dependent on whether the previous crew or maintenance did it. If that’s the case, I might as well start questioning every single procedure Airbus publishes. How many times have you, during your preflt, found something that’s not right yet it was supposed to be catched on the first flight of the day! Do yourself and your crew a favour and test the thing as instructed on the manual, whether the APU is off or on (as nothing happens). Takes not longer than 3 seconds and who knows, maybe one day you’ll even catch a fault that happened to you but not the previous crew