Bluetooth Headphones Independent Volume Control

I have seen this asked before, but no resolution has been presented. I have had this issue for years.

When the iPhone is connected to my Bluetooth headphones, the volume control buttons on the headphones sync with the volume slider on the iPhone, and the minimum volume is too loud. It seems that the volume of the Bluetooth device itself is set to the maximum, and then the controls on the Bluetooth device control the volume slider on the iPhone, instead of being able to control the volume of the Bluetooth device.

Occasionally, when paired with the Bluetooth device, the volume controls don't sync, and the volume controls on the Bluetooth device do not control the volume slider on the iPhone, but instead control the volume of the Bluetooth device itself. This is the desired behavior, and allows the volume to be adjusted down to an appropriate level, but this only happens rarely, and I cannot find a way to reproduce this (forgetting the Bluetooth device and re-pairing, power cycling the two devices in different orders, etc).

Also note, adjusting the maximum volume level on the iPhone does not help this issue since the volume slider on the iPhone is not what is causing the volume to be too loud. I just upgraded to the iPhone 12 and was hoping that this issue might be resolved, but it is still an issue.