I'm still confused. I thought you want to create KM Macros that will REPLACE the XK-24.
If that is what you want, then I'd guess that KM Palettes would be one good choice.
I'm not a pallet expert, but I think that you would need to create a separate Macro Group for each unique set of Macros that you will need. If every web site and app that you were controlling with the XK-24 is truly unique, then you will need a separate MG/pallet for each.
I'd expect one or more of our local pallet gurus to jump in here and offer some more specific suggestions.
BTW, just so you know, each Macro can have one or more triggers. This mean that you could have multiple hotkeys to trigger the same functionality, if that is of any use to you. Further more, you can get the hotkey that triggered the macro, and branch in the Macro using Switch Actions and/or IF/THEN Actions.
EDIT: Here's an example that may help:
Nested palettes w/ single key hotkeys best practices