SUMMARY
I was trying to assign more than one key bind to the task switcher, like walking through all/current windows forward/backward. But I found:

Keybindings in "Shortcut" menu only activates the switcher, it's the keybindings in Task Switcher menu that tells the switcher to walk forward/backward.
The keybinding setting in "Task Switcher" menu doesn't allow multiple bindings. Pressing "Meta+Tab then Meta+J" will assign a keystroke combo to it, not 2 bindings.
Also, assigning keybinding in Task Switcher menu will assign a keybinding in Shortcut menu and vice versa. 
So what's the point of making 2 separate shortcut menus anyways? Why not just use a single one? To me it's kinda like sacrificing the ability of assigning multiple bindings to gain the ability of assigning a combo.

So I think it would be better if:
1. Remove the settings in Task Switcher menu and make the switcher solely rely on the bindings in Shortcut menu
2. Or, let the settings in 2 menus share a same set of settings: user can assign multiple bindings in Task Switcher menu, all changes in Task Switcher menu will affect Shortcut menu too and vice versa, since they share a same set of settings. This will ofc remove the ability of assigning a keystroke combo (but who uses a combo to hop through windows??)

STEPS TO REPRODUCE
1. Clear Walk Through Windows and Walk Through Windows (Reverse) in Shortcut menu 
2. Assign Meta+Tab and Meta+J to Walk Through Windows in Shortcut menu

OBSERVED RESULT
Only Meta+J is automatically assigned in Task Switcher menu as "Forward"
Pressing Meta+Tab will only activate the switcher, pressing it twice has no effect.
Pressing Meta+J will activate the switcher, pressing it twice makes the switcher walks forward.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: 
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION