Ah, yes, you are right about KEY_HOME (<start> code in kodi). The global section maps that to PreviousMenu, but in FullscreenVideo it's changed to OSD.
Not 100% sure about the window names, have a look here for the list of Window IDs: Window IDs - Official Kodi Wiki - the links to Keymaps and Action IDs at the bottom of the page might also be worth a read.
so long,
Hias