The iPhone lovingly reducing the volume claiming to protect your hearing (a feature that seems impossible to disable even after changing the phone’s region) as an added iOS 14 feature was a volume control “option” that I found annoying and insanely unsafe. I don’t even think there was initially an option to disable it for specific outputs. The best part was at that stage when it kept nearly muting itself in my car while I was driving and had the windows down, taking my attention away from the road forcing me to fiddle with the volume up button. I know that it’s possible to mark each individual output as “other” now but it’s still kind of insane to force this on users.
“Reduce loud sounds automatically“ cannot be turned off here, not even if you change your region. The only real solution is to keep classifying Bluetooth sound outputs and lighting adapters manually when you connect a new one. I’m fairly certain that even that feature was added in after they implemented the main automatic volume limit thingy because I remember looking through every option and forum for a solution. It for me annoyed enough that I was considering going back to Android at that time.