Reddit post: https://www.reddit.com/r/Windows11/comments/1qc3f2b/new_in_windhawk_perapp_volume_control_on_the/
"Don't you think that opening the Windows volume mixer is a bit of a hassle? Control the per-app volume by scrolling over taskbar buttons with this new mod!"
AlomWare Toolbox solution: No, it's not a hassle to change an app's volume level with AlomWare Toolbox! :) One of our savvy users (Bazza) posted a way to change the volume of the active app simply by pressing a hotkey and where the mouse was vertically on the desktop. If the mouse was at the top, the volume for that app would be set to 100%. If at the bottom, mute. In the middle, 50% volume. You get the idea.
Unlike what is mentioned in the above Reddit post, there's no tweaks or mods to install and no damage risks to your PC by editing the Registry. All cleanly done by the portable nature of AlomWare Toolbox, and you don't need to click or scroll over anything to change the volume.
The link to Bazza's post: https://www.alomware.com/forum/index.php?topic=15.msg108#msg108
Thanks for the tip, Bazza! 8)