Show volume overlay only when controlling system volume?

[gtebbutt]

Firstly, great tool, thank you! Interestingly the binary seems to work fine for me on Ventura 13.2.1 (Intel MBP) - not sure if that's Intel specific or something in my system config, but either way it's a bonus.

Just wanted to check if two small things are possible:

• Can it be set to display the volume feedback bezel only when controlling the system volume, but not when controlling Spotify? Right now it looks like it's globally on/off, but it'd be useful to have that difference in visual feedback to know when it's changing at the system level if possible.
• Extremely minor, but is there any way to change the increment from 6% to 6.25%, so that the "blocks" match up with the system UI overlay? This is purely aesthetic, but if it's easily done via a config file or something it'd be nice to have.

For context, I'm using this with inverted modifier turned on and using QMK macros to automatically insert the ⌘, so that the normal volume keys still control system volume (for alerts, video calls, etc. as expected), but the physical volume dial on the keyboard maps directly to Spotify and controls the wireless speakers.

I'm hoping to make it "invisible" - Spotify control is hidden and just happens, and system control behaves identically to the default - so a possible alternative would be just to have a setting not to intercept volume keystrokes at all unless the modifier is pressed?