How do I choose a dialog option with keyboard, but without TAB?
Try  Cmd ⌘   A  or  Cmd ⌘    Shift ⇧   A  

They're a bit hit &amp; miss as to which works in any given circumstance, but [key/keys] + [first letter] will usually do it.

btw, you can toggle the Tab behaviour on &amp; off at will with  Ctrl ⌃    F7  even whilst the dialog is open.