It doesn't matter whether you use Xorg or Wayland, in KDE you can configure shortcuts the same way either way. Edit: As pointed out by a comment, since version 5.25, Custom Shortcuts are no longer available in KDE + Wayland.
KDE has built-in shortcut configuration tools. "Shortcuts" for pre-defined functions specified by your installed apps and "Custom Shortcuts". You can access them by using the systemsettings kcm_keys command.
In the "Shortcuts" menu, scroll down to "KWin" and select it. On the right you get a list of window manager shortcuts. For me, the relevant key combos are set for "Quick Tile Window to the Left" and so on. You can clear those now, but they are automatically cleared if you use them for something else.
Since you want to remap the keys to a different keyboard input, you'll have to use the "Custom Shortcuts" tool, so click on that in the left panel. Here you have a list of your custom shortcuts and an "Edit" menu button at the bottom. Click that button, and then select "New" -> "Global Shortcut" -> "Send Keyboard Input".
In the "Trigger" tab for the new shortcut, you can assign your key combo. If you haven't cleared it before, it will ask you whether you want to reassign it, so click "Reassign".
In the "Action" tab, you can define a keyboard input combo in the text field at the top. For simultaneous input, connect key names with +, for sequential input, connect them with :. The correct names are listed here, from line 393 onwards, in quotation marks near the end of each line: https://github.com/qt/qtbase/blob/f89c4c4f8fd5afbb6a5480fe2fc13bb6dcaace47/src/gui/kernel/qkeysequence.cpp#L393
For the inputs you want, use these codes (obviously you have to make a separate shortcut for each):
In the "Window" section, simply leave "Active window" selected. Click "Apply" to save your changes. You can also add a description and a name for each shortcut, or create a "group" in the list of custom shortcuts to keep them organized.
