I have mapped the Move Focus to the menu bar to CMD - '. This works for example, on Chrome. It also happens to work in Word: you can see the Apple icon is activated, so then I can use mnemonics (first letter) of the menu items to get to the submenu e.g. V for View:

It does not however work for Excel or PowerPoint. I even tried the default Ctl - F2 as well as CMD - F2): nothing works to get to the menu.

I am a keyboardist and slowed down [and annoyed] quite a bit by needing to jump to the mouse for everything. Is there a workaround/fix?