My main gripe is that 90% of the time I go to tap on the speaker icon to change the volume, the app opens unintentionally because the speaker is too small.

So, I suggest to change the hotspot area so that anywhere in the green area will open the quick access volume control. Maybe this could also be extended so that only the blue area opens the app, pink are back/stop/ffwd and yellow is room selection. Tapping in the area outside any of these will just be a dead zone.

Please see my crude illustration…