SUMMARY
When adjusting the volume with keyboard hotkeys on a multi-display set up, currently, the OSD volume slider/indicator pop-up will display only on the monitor that the mouse cursor is active on. It would be a nice (wishlist) feature to be able to have it display on all monitors at the same time regardless of mouse cursor position. This would increase visibility of system volume adjustment.

STEPS TO REPRODUCE
1.  Ensure your mouse in on the display you would like the OSD volume slider/indicator pop-up to appear on.
2.  Mouse Scroll Up/Down on the "Audio Devices" system tray item, or use keyboard hotkeys to adjust volume.

OBSERVED RESULT:
OSD pop-up displays on whichever monitor the cursor exists on.

EXPECTED RESULT:
An additional settings parameter in the configuration menu that allows the OSD pop-up to display on all monitors, regardless of mouse cursor location. 

SOFTWARE/OS VERSIONS
Windows: N/A
macOS: N/A
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Fedora KDE 42 6.15.7-200.fc42.x86_64
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION
This is merely a feature request that I personally would find quite useful and would help increase visibility. Unsure if other users would benefit from this feature as well. I could be alone in this!