I'm using Kubuntu 20.04 (KDE), but it would also be helpful to know how to do this on other official Ubuntu flavors.
On KDE, ALT+L Mouse and ALT+R Mouse are global keyboard shortcuts to move and resize windows.
I experience problems when I try to use conflicting shortcuts in applications like Blender. For example, ALT+R Mouse in Blender should allow me to loop select with the selection tool, but due to the global shortcut, it actually results in me grabbing the entire window to move it.
In most cases, it's easier to rebind the shortcut on the application itself than mess with global shortcuts, but Blender has so many shortcuts that I don't want to deviate from the default shortcuts in order to learn from tutorials and documentation.
I want to be able to use shortcuts in Blender that use the ALT key, but I don't want to disable the global shortcuts altogether. I find them to be a huge quality of life improvement for window management.
I would like to know how to disable global shortcuts on a per-application basis.
There is similar question "Disable global keyboard shortcuts for specific application" but it specifically pertains to GNOME2