Sideloaded app on Denza B5

Hi all. I am looking to buy a denza b5 flagship from someone here in qatar. The guy has an app called gbox installed (sideloaded) by some garage here. I called and asked a denza technician and he said that “technically it voids the warranry for anything related to the infotainment system and electronics as per BYD china instructions” but that they “turn a blind eye as much as they can” and that “you can delete the app and no one would know”. My questions are 1) is it really the case that “no one would know” if gbox is deleted? Or will there be any remnants that can be detected and 2) for anyone who has experience with this, how risky is it and should i just avoid it? Thanks