Changing default Keynote shortcuts

Keynote has its own shortcuts that overrides mac shortcuts. For example, moving focus between windows is generally ⌘ Cmd-< on Mac, but in Keynote this is Zoom out. Adding ⌘ Cmd-< as the shortcut to change between windows in Keynote in System preferences > App shortcuts does not work for me.

Is there another way of fixing this? I often have several Keynote windows open at the same time and I need a way to change between the efficiently without using the mouse, preferably in the same way as on Mac generally. Zooming in and out in Keynote is not as important, but if this could be changed to ⌘ Cmd-+ and ⌘ Cmd--, that would be great too.