Not sure how feasible or if even within the scope of BT, but one feature that would be really nice is the ability to set a volume dynamic range per app and system-wide, with the ability to quickly toggle it on and off, with the setting(s) remembered, and maybe even have it auto-enable/disable based on time. For example, I could set my media player to stay within +/-x dB (or whatever measurement BT could monitor/use) of the set volume. This way there wouldn't be any really loud noises compared to the "average" volume. Totally understand if this would be too complex, as it would likely require actually processing the audio, "listening" to and adjusting it real-time, vs simply changing the volume.