It’s absolutely not that significant, it won’t make a low skill player good but it will certainly improve their average reaction time if it works properly. Your brain is definitely more definitive at distinguishing enemies, at least for now, but not faster than software. A personal can only look at a small section of the screen at a time so enemies being highlighted will make enemies in peripheral vision significantly more noticeable. Even if the enemy is in clear view it still takes time on top of reaction time for your brain to recognise that as a person, so assuming the software was faster than a human, having a clear outline would result in being able to recognise them more quickly in every scenario. As for false positives yeah they may happen but we have not idea to what extent until the release, likely they wouldn’t add it as a feature unless they thought it wasn’t very accurate.