I Agree paying attention to details very important to have a proper functioning software, even more so critical for Antivirus/Malware protection products and Operating systems, Sure a small bug may slip thru now and then, but show stopper bugs shouldn't, and others customers have come accustomed to as well should work fine
Sure it's hard to test i'm sure of every possible configuration in the real world, as theres millions of PC's, configured all sorts of ways, Intel, AMD processors, different memory configurations, hard drives, ssd, etc , but testing for the most common processors, chipset, and such hopefully contrails as many bugs as possible.
Bug Free version of Avast would be perfect to go along with the upcoming Spring Release of Redstone 4 for Windows 10, hopefully we will see that and perfect, Trying Defender on my Insiders PC, left me missing Avast even on that system lol, as something broke Defender last night, probably some engine update they sent, as can't get it to even scan now, so can't wait for Redstone 4 final, and Avast will work again on it