How to keep keyboard shortcuts working when Timeline loses focus?

I have a tourbox device and want to have horizontal zoom in/out of the current sequence always assigned and available to one of the wheels on it. Unfortunately, any time another panel has focus, the wheel changes to zooming the program or even the effects control panel. If I preface the command with the F3 key to force focus back on the timeline, it “works”, but if multiple sequences are open, and it alread has focus, it toggles to another sequence instead because of the poor decision to double up that mapping of F3 (both focus and cycle through open sequences).  This seems like the most elementary function, but is seemingly impossible to accomplish.