We are committed to keeping the world of Sanctuary a safe and fair place for all players, and our Game Security team constantly monitors for cheats and unauthorized modifications. All Diablo IV players agree to the Blizzard EULA as a condition of playing the game. The Blizzard EULA explicitly prohi...
"With that in mind, we want to make it clear that TurboHUD4, like any game-modifying software, is prohibited for use with Diablo IV. Players who install this kind of software will put their accounts at risk for disciplinary action, which can include permanent suspension."
Overlay type of mods are always kind of critical because they simply work in a very similar way to map hacks and bots, using often the same type of functions. Even if it wouldn't offer anything offensive it would still likely be something their anticheat systems catch as a positive.
They haven’t but I don’t think that applies here as it shouldn’t modify any of the game files. I haven’t heard of it being an issue with other games either but I also don’t keep an eagle eye on that stuff.