dagaloni Kagi has both "Bookmarks bar" and "Favorites" which are separate for more robustness and utility, unlike Safari. The shortcuts work for Bookmarks Bar items.
Adding opt cmd number to work when the option is selected - seems like a reasonalbe idea.
We decided to tie this option to switching tabs because it is arguably more used then for selecting bookmarks. We wanted people to discover they can switch tabs with shortcuts.
After you play with this all please feel free to suggest changes having in mind that things in Orion are not always meant to work exactly the same like in Safari (we try to make them better).