If you’re on Android, go to Developer Options, search for “Disable absolute volume” and turn it on. It gives you more volume steps - the headphones and phone have two separate volume controls.

For DAC mode, there’s no fix. But 3.5mm mode is good with an amp!

If you don’t have Developer Options, you have to go in About -> Software -> Tap “build number” many times to unlock them

I’d recommend an AutoEQ app, like Poweramp Equalizer or something else. The Rtings preset for XM5 sounds great. I tweaked it a bit, and it sounds clearer than Bathys now. Technicalities are pretty close, surprisingly.

Bathys still has a wider stage, but I can’t fix the timbre and bass issues with EQ.